diff --git a/src/Microsoft.AspNetCore.Razor.Evolution/DefaultRazorIRLoweringPhase.cs b/src/Microsoft.AspNetCore.Razor.Evolution/DefaultRazorIRLoweringPhase.cs
index 2680ab2b63..39487a68d5 100644
--- a/src/Microsoft.AspNetCore.Razor.Evolution/DefaultRazorIRLoweringPhase.cs
+++ b/src/Microsoft.AspNetCore.Razor.Evolution/DefaultRazorIRLoweringPhase.cs
@@ -22,20 +22,10 @@ namespace Microsoft.AspNetCore.Razor.Evolution
 
             document.Options = syntaxTree.Options;
 
-            var namespaces = new HashSet<string>();
-
-            var i = 0;
-            foreach (var namespaceImport in syntaxTree.Options.NamespaceImports)
+            var namespaces = new Dictionary<string, SourceSpan?>(StringComparer.Ordinal);
+            foreach (var defaultNamespace in syntaxTree.Options.NamespaceImports)
             {
-                if (namespaces.Add(namespaceImport))
-                {
-                    var @using = new UsingStatementIRNode()
-                    {
-                        Content = namespaceImport,
-                    };
-
-                    builder.Insert(i++, @using);
-                }
+                namespaces[defaultNamespace] = null;
             }
 
             var checksum = ChecksumIRNode.Create(codeDocument.Source);
@@ -64,6 +54,21 @@ namespace Microsoft.AspNetCore.Razor.Evolution
 
             visitor.VisitBlock(syntaxTree.Root);
 
+            // In each lowering piece above, namespaces were tracked. We render them here to ensure every
+            // lowering action has a chance to add a source location to a namespace. Ultimately, closest wins.
+
+            var i = builder.Current.Children.IndexOf(checksum) + 1;
+            foreach (var @namespace in namespaces)
+            {
+                var @using = new UsingStatementIRNode()
+                {
+                    Content = @namespace.Key,
+                    Source = @namespace.Value,
+                };
+
+                builder.Insert(i++, @using);
+            }
+
             codeDocument.SetIRDocument(document);
         }
 
@@ -71,9 +76,9 @@ namespace Microsoft.AspNetCore.Razor.Evolution
         {
             protected readonly RazorIRBuilder _builder;
             protected readonly DocumentIRNode _document;
-            protected readonly HashSet<string> _namespaces;
+            protected readonly Dictionary<string, SourceSpan?> _namespaces;
 
-            public LoweringVisitor(DocumentIRNode document, RazorIRBuilder builder, HashSet<string> namespaces)
+            public LoweringVisitor(DocumentIRNode document, RazorIRBuilder builder, Dictionary<string, SourceSpan?> namespaces)
             {
                 _document = document;
                 _builder = builder;
@@ -85,16 +90,8 @@ namespace Microsoft.AspNetCore.Razor.Evolution
             public override void VisitImportSpan(AddImportChunkGenerator chunkGenerator, Span span)
             {
                 var namespaceImport = chunkGenerator.Namespace.Trim();
-
-                // Track seen namespaces so we don't add duplicates from options.
-                if (_namespaces.Add(namespaceImport))
-                {
-                    _builder.Add(new UsingStatementIRNode()
-                    {
-                        Content = namespaceImport,
-                        Source = BuildSourceSpanFromNode(span),
-                    });
-                }
+                var namespaceSpan = BuildSourceSpanFromNode(span);
+                _namespaces[namespaceImport] = namespaceSpan;
             }
 
             public override void VisitAddTagHelperSpan(AddTagHelperChunkGenerator chunkGenerator, Span span)
@@ -179,7 +176,7 @@ namespace Microsoft.AspNetCore.Razor.Evolution
             // this simple.
             private bool _insideLineDirective;
 
-            public ImportsVisitor(DocumentIRNode document, RazorIRBuilder builder, HashSet<string> namespaces)
+            public ImportsVisitor(DocumentIRNode document, RazorIRBuilder builder, Dictionary<string, SourceSpan?> namespaces)
                 : base(document, builder, namespaces)
             {
             }
@@ -223,7 +220,7 @@ namespace Microsoft.AspNetCore.Razor.Evolution
             private DeclareTagHelperFieldsIRNode _tagHelperFields;
             private readonly string _tagHelperPrefix;
 
-            public MainSourceVisitor(DocumentIRNode document, RazorIRBuilder builder, HashSet<string> namespaces, string tagHelperPrefix)
+            public MainSourceVisitor(DocumentIRNode document, RazorIRBuilder builder, Dictionary<string, SourceSpan?> namespaces, string tagHelperPrefix)
                 : base(document, builder, namespaces)
             {
                 _tagHelperPrefix = tagHelperPrefix;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Basic.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Basic.cs
index c33ee51700..91e1ad3c3c 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Basic.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Basic.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = global::System.Object;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Basic.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Basic.mappings.txt
index 0c9b50dd68..69945e111a 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Basic.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Basic.mappings.txt
@@ -1,10 +1,10 @@
 Source Location: (13:0,13 [4] /TestFiles/Input/Basic.cshtml)
 |logo|
-Generated Location: (1024:42,13 [4] )
+Generated Location: (1063:46,13 [4] )
 |logo|
 
 Source Location: (43:2,5 [21] /TestFiles/Input/Basic.cshtml)
 |Html.Input("SomeKey")|
-Generated Location: (1109:47,6 [21] )
+Generated Location: (1148:51,6 [21] )
 |Html.Input("SomeKey")|
 
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Inject.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Inject.cs
index 33296c6a56..e447392aa2 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Inject.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Inject.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = global::System.Object;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Inject.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Inject.mappings.txt
index c6f137ea6c..8963a8b946 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Inject.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Inject.mappings.txt
@@ -1,15 +1,15 @@
 Source Location: (1:0,1 [17] /TestFiles/Input/Inject.cshtml)
 |using MyNamespace|
-Generated Location: (574:32,0 [17] )
+Generated Location: (613:36,0 [17] )
 |using MyNamespace|
 
 Source Location: (28:1,8 [5] /TestFiles/Input/Inject.cshtml)
 |MyApp|
-Generated Location: (869:41,0 [5] )
+Generated Location: (908:45,0 [5] )
 |MyApp|
 
 Source Location: (34:1,14 [14] /TestFiles/Input/Inject.cshtml)
 |MyPropertyName|
-Generated Location: (971:45,14 [14] )
+Generated Location: (1010:49,14 [14] )
 |MyPropertyName|
 
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithModel.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithModel.cs
index b9ae9f51b6..49f3f2623a 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithModel.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithModel.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = MyModel;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithModel.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithModel.mappings.txt
index c71e253e17..cec2a3c8b8 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithModel.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithModel.mappings.txt
@@ -1,25 +1,25 @@
 Source Location: (7:0,7 [7] /TestFiles/Input/InjectWithModel.cshtml)
 |MyModel|
-Generated Location: (771:36,0 [7] )
+Generated Location: (810:40,0 [7] )
 |MyModel|
 
 Source Location: (24:1,8 [5] /TestFiles/Input/InjectWithModel.cshtml)
 |MyApp|
-Generated Location: (861:40,0 [5] )
+Generated Location: (900:44,0 [5] )
 |MyApp|
 
 Source Location: (30:1,14 [14] /TestFiles/Input/InjectWithModel.cshtml)
 |MyPropertyName|
-Generated Location: (963:44,14 [14] )
+Generated Location: (1002:48,14 [14] )
 |MyPropertyName|
 
 Source Location: (54:2,8 [17] /TestFiles/Input/InjectWithModel.cshtml)
 |MyService<TModel>|
-Generated Location: (1047:48,0 [17] )
+Generated Location: (1086:52,0 [17] )
 |MyService<TModel>|
 
 Source Location: (72:2,26 [4] /TestFiles/Input/InjectWithModel.cshtml)
 |Html|
-Generated Location: (1161:52,14 [4] )
+Generated Location: (1200:56,14 [4] )
 |Html|
 
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithSemicolon.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithSemicolon.cs
index 1cbc1e070d..59d83e9be2 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithSemicolon.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithSemicolon.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = MyModel;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithSemicolon.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithSemicolon.mappings.txt
index 4e2caf43c1..39314f0860 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithSemicolon.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/InjectWithSemicolon.mappings.txt
@@ -1,45 +1,45 @@
 Source Location: (7:0,7 [7] /TestFiles/Input/InjectWithSemicolon.cshtml)
 |MyModel|
-Generated Location: (775:36,0 [7] )
+Generated Location: (814:40,0 [7] )
 |MyModel|
 
 Source Location: (24:1,8 [5] /TestFiles/Input/InjectWithSemicolon.cshtml)
 |MyApp|
-Generated Location: (865:40,0 [5] )
+Generated Location: (904:44,0 [5] )
 |MyApp|
 
 Source Location: (30:1,14 [14] /TestFiles/Input/InjectWithSemicolon.cshtml)
 |MyPropertyName|
-Generated Location: (967:44,14 [14] )
+Generated Location: (1006:48,14 [14] )
 |MyPropertyName|
 
 Source Location: (58:2,8 [17] /TestFiles/Input/InjectWithSemicolon.cshtml)
 |MyService<TModel>|
-Generated Location: (1051:48,0 [17] )
+Generated Location: (1090:52,0 [17] )
 |MyService<TModel>|
 
 Source Location: (76:2,26 [4] /TestFiles/Input/InjectWithSemicolon.cshtml)
 |Html|
-Generated Location: (1165:52,14 [4] )
+Generated Location: (1204:56,14 [4] )
 |Html|
 
 Source Location: (93:3,8 [5] /TestFiles/Input/InjectWithSemicolon.cshtml)
 |MyApp|
-Generated Location: (1239:56,0 [5] )
+Generated Location: (1278:60,0 [5] )
 |MyApp|
 
 Source Location: (99:3,14 [15] /TestFiles/Input/InjectWithSemicolon.cshtml)
 |MyPropertyName2|
-Generated Location: (1341:60,14 [15] )
+Generated Location: (1380:64,14 [15] )
 |MyPropertyName2|
 
 Source Location: (129:4,8 [17] /TestFiles/Input/InjectWithSemicolon.cshtml)
 |MyService<TModel>|
-Generated Location: (1426:64,0 [17] )
+Generated Location: (1465:68,0 [17] )
 |MyService<TModel>|
 
 Source Location: (147:4,26 [5] /TestFiles/Input/InjectWithSemicolon.cshtml)
 |Html2|
-Generated Location: (1540:68,14 [5] )
+Generated Location: (1579:72,14 [5] )
 |Html2|
 
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Model.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Model.cs
index 60a6f4a56e..8a3343ee6a 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Model.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Model.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = System.Collections.IEnumerable;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Model.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Model.mappings.txt
index 5078bb289a..52a3fc478c 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Model.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/Model.mappings.txt
@@ -1,5 +1,5 @@
 Source Location: (7:0,7 [30] /TestFiles/Input/Model.cshtml)
 |System.Collections.IEnumerable|
-Generated Location: (807:36,0 [30] )
+Generated Location: (846:40,0 [30] )
 |System.Collections.IEnumerable|
 
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.cs
index e18f009f49..2307ec3acc 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = DateTime;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.mappings.txt
index 9d6d23bcd9..8eb8a16540 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.mappings.txt
@@ -1,20 +1,20 @@
 Source Location: (7:0,7 [8] /TestFiles/Input/ModelExpressionTagHelper.cshtml)
 |DateTime|
-Generated Location: (782:36,0 [8] )
+Generated Location: (821:40,0 [8] )
 |DateTime|
 
 Source Location: (33:2,14 [108] /TestFiles/Input/ModelExpressionTagHelper.cshtml)
 |Microsoft.AspNetCore.Mvc.Razor.Extensions.InputTestTagHelper, Microsoft.AspNetCore.Mvc.Razor.Extensions.Test|
-Generated Location: (903:40,30 [108] )
+Generated Location: (942:44,30 [108] )
 |Microsoft.AspNetCore.Mvc.Razor.Extensions.InputTestTagHelper, Microsoft.AspNetCore.Mvc.Razor.Extensions.Test|
 
 Source Location: (162:4,17 [3] /TestFiles/Input/ModelExpressionTagHelper.cshtml)
 |Now|
-Generated Location: (1798:52,144 [3] )
+Generated Location: (1837:56,144 [3] )
 |Now|
 
 Source Location: (189:5,18 [5] /TestFiles/Input/ModelExpressionTagHelper.cshtml)
 |Model|
-Generated Location: (2199:58,136 [5] )
+Generated Location: (2238:62,136 [5] )
 |Model|
 
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/MultipleModels.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/MultipleModels.cs
index 3628dd6ed9..549af844fa 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/MultipleModels.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/MultipleModels.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = System.Collections.IEnumerable;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/MultipleModels.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/MultipleModels.mappings.txt
index 912bec6f23..dd25af98cc 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/MultipleModels.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/MultipleModels.mappings.txt
@@ -1,10 +1,10 @@
 Source Location: (7:0,7 [21] /TestFiles/Input/MultipleModels.cshtml)
 |ThisShouldBeGenerated|
-Generated Location: (816:36,0 [21] )
+Generated Location: (855:40,0 [21] )
 |ThisShouldBeGenerated|
 
 Source Location: (37:1,7 [30] /TestFiles/Input/MultipleModels.cshtml)
 |System.Collections.IEnumerable|
-Generated Location: (920:40,0 [30] )
+Generated Location: (959:44,0 [30] )
 |System.Collections.IEnumerable|
 
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPages.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPages.cs
index ff0a57a8f9..79cc0d09bb 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPages.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPages.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = NewModel;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPages.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPages.mappings.txt
index 010562f8fb..d67efe59af 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPages.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPages.mappings.txt
@@ -1,21 +1,21 @@
 Source Location: (60:4,1 [41] /TestFiles/Input/RazorPages.cshtml)
 |using Microsoft.AspNetCore.Mvc.RazorPages|
-Generated Location: (565:32,0 [41] )
+Generated Location: (604:36,0 [41] )
 |using Microsoft.AspNetCore.Mvc.RazorPages|
 
 Source Location: (16:2,7 [8] /TestFiles/Input/RazorPages.cshtml)
 |NewModel|
-Generated Location: (879:41,0 [8] )
+Generated Location: (918:45,0 [8] )
 |NewModel|
 
 Source Location: (40:3,14 [17] /TestFiles/Input/RazorPages.cshtml)
 |"*, TestAssembly"|
-Generated Location: (999:45,29 [17] )
+Generated Location: (1038:49,29 [17] )
 |"*, TestAssembly"|
 
 Source Location: (666:28,47 [4] /TestFiles/Input/RazorPages.cshtml)
 |Name|
-Generated Location: (1500:57,47 [4] )
+Generated Location: (1539:61,47 [4] )
 |Name|
 
 Source Location: (117:6,12 [360] /TestFiles/Input/RazorPages.cshtml)
@@ -36,7 +36,7 @@ Source Location: (117:6,12 [360] /TestFiles/Input/RazorPages.cshtml)
         public string Name { get; set; }
     }
 |
-Generated Location: (1929:68,12 [360] )
+Generated Location: (1968:72,12 [360] )
 |
     public class NewModel : PageModel
     {
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPagesWithoutModel.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPagesWithoutModel.cs
index 09cdff3487..3a84630520 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPagesWithoutModel.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPagesWithoutModel.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = _TestFiles_Input_RazorPagesWithoutModel_cshtml;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPagesWithoutModel.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPagesWithoutModel.mappings.txt
index 84f6991a97..2eac6250c2 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPagesWithoutModel.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/RazorPagesWithoutModel.mappings.txt
@@ -1,16 +1,16 @@
 Source Location: (43:3,1 [41] /TestFiles/Input/RazorPagesWithoutModel.cshtml)
 |using Microsoft.AspNetCore.Mvc.RazorPages|
-Generated Location: (615:32,0 [41] )
+Generated Location: (654:36,0 [41] )
 |using Microsoft.AspNetCore.Mvc.RazorPages|
 
 Source Location: (23:2,14 [17] /TestFiles/Input/RazorPagesWithoutModel.cshtml)
 |"*, TestAssembly"|
-Generated Location: (970:41,29 [17] )
+Generated Location: (1009:45,29 [17] )
 |"*, TestAssembly"|
 
 Source Location: (571:24,47 [4] /TestFiles/Input/RazorPagesWithoutModel.cshtml)
 |Name|
-Generated Location: (1483:53,47 [4] )
+Generated Location: (1522:57,47 [4] )
 |Name|
 
 Source Location: (100:5,12 [283] /TestFiles/Input/RazorPagesWithoutModel.cshtml)
@@ -28,7 +28,7 @@ Source Location: (100:5,12 [283] /TestFiles/Input/RazorPagesWithoutModel.cshtml)
         public string Name { get; set; }
     }
 |
-Generated Location: (1924:64,12 [283] )
+Generated Location: (1963:68,12 [283] )
 |
     public IActionResult OnPost(Customer customer)
     {
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/_ViewImports.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/_ViewImports.cs
index 7084cd9aa9..f1bd171e75 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/_ViewImports.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/_ViewImports.cs
@@ -2,7 +2,11 @@ namespace AspNetCore
 {
     #line hidden
     using TModel = global::System.Object;
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/_ViewImports.mappings.txt b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/_ViewImports.mappings.txt
index 1819892628..735a62867f 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/_ViewImports.mappings.txt
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/DesignTime/_ViewImports.mappings.txt
@@ -1,10 +1,10 @@
 Source Location: (8:0,8 [19] /TestFiles/Input/_ViewImports.cshtml)
 |IHtmlHelper<TModel>|
-Generated Location: (782:36,0 [19] )
+Generated Location: (821:40,0 [19] )
 |IHtmlHelper<TModel>|
 
 Source Location: (28:0,28 [5] /TestFiles/Input/_ViewImports.cshtml)
 |Model|
-Generated Location: (898:40,14 [5] )
+Generated Location: (937:44,14 [5] )
 |Model|
 
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Basic.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Basic.cs
index d435c38d3a..a527fe7ecc 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Basic.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Basic.cs
@@ -2,7 +2,11 @@
 namespace AspNetCore
 {
     #line hidden
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Inject.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Inject.cs
index 87ea7c88f6..ec750e94e3 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Inject.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Inject.cs
@@ -2,7 +2,11 @@
 namespace AspNetCore
 {
     #line hidden
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/InjectWithModel.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/InjectWithModel.cs
index 233b319695..906c5b254e 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/InjectWithModel.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/InjectWithModel.cs
@@ -2,7 +2,11 @@
 namespace AspNetCore
 {
     #line hidden
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/InjectWithSemicolon.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/InjectWithSemicolon.cs
index 9ffb69365d..2bb0b7094c 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/InjectWithSemicolon.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/InjectWithSemicolon.cs
@@ -2,7 +2,11 @@
 namespace AspNetCore
 {
     #line hidden
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Model.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Model.cs
index 1e7acc5279..75be3e3e44 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Model.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/Model.cs
@@ -2,7 +2,11 @@
 namespace AspNetCore
 {
     #line hidden
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/ModelExpressionTagHelper.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/ModelExpressionTagHelper.cs
index 2d1be87f90..d51ade6a77 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/ModelExpressionTagHelper.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/ModelExpressionTagHelper.cs
@@ -2,7 +2,11 @@
 namespace AspNetCore
 {
     #line hidden
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/RazorPages.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/RazorPages.cs
index 249d9368ac..0e0169b1a9 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/RazorPages.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/RazorPages.cs
@@ -2,7 +2,11 @@
 namespace AspNetCore
 {
     #line hidden
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/RazorPagesWithoutModel.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/RazorPagesWithoutModel.cs
index 3467fba161..1c424b7f87 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/RazorPagesWithoutModel.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/RazorPagesWithoutModel.cs
@@ -2,7 +2,11 @@
 namespace AspNetCore
 {
     #line hidden
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/_ViewImports.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/_ViewImports.cs
index 50689f6715..5818c886a9 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/_ViewImports.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/Output/Runtime/_ViewImports.cs
@@ -2,7 +2,11 @@
 namespace AspNetCore
 {
     #line hidden
-    using System;
+#line 1 ""
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 2 ""
 using System.Linq;
diff --git a/test/Microsoft.AspNetCore.Razor.Evolution.Test/DefaultRazorIRLoweringPhaseIntegrationTest.cs b/test/Microsoft.AspNetCore.Razor.Evolution.Test/DefaultRazorIRLoweringPhaseIntegrationTest.cs
index 9d6fff7a3e..4bf813264e 100644
--- a/test/Microsoft.AspNetCore.Razor.Evolution.Test/DefaultRazorIRLoweringPhaseIntegrationTest.cs
+++ b/test/Microsoft.AspNetCore.Razor.Evolution.Test/DefaultRazorIRLoweringPhaseIntegrationTest.cs
@@ -155,6 +155,7 @@ namespace Microsoft.AspNetCore.Razor.Evolution
         {
             // Arrange
             var codeDocument = TestRazorCodeDocument.Create(@"@using System");
+            var expectedSourceLocation = new SourceSpan(codeDocument.Source.FileName, 1, 0, 1, 12);
 
             // Act
             var irDocument = Lower(codeDocument);
@@ -162,7 +163,11 @@ namespace Microsoft.AspNetCore.Razor.Evolution
             // Assert
             Children(irDocument,
                 n => Checksum(n),
-                n => Using("System", n),
+                n =>
+                {
+                    Using("System", n);
+                    Assert.Equal(expectedSourceLocation, n.Source);
+                },
                 n => Using(typeof(Task).Namespace, n));
         }
 
diff --git a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.codegen.cs b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.codegen.cs
index 9e2b6a6e0c..c78fe83b15 100644
--- a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.codegen.cs
+++ b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.codegen.cs
@@ -1,7 +1,11 @@
 namespace Microsoft.AspNetCore.Razor.Evolution.IntegrationTests.TestFiles
 {
     #line hidden
-    using System;
+#line 3 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml"
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 1 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml"
 using System.IO;
diff --git a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.ir.txt b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.ir.txt
index 63cc99fa5a..3ffbd16c94 100644
--- a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.ir.txt
+++ b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.ir.txt
@@ -1,7 +1,7 @@
 Document - 
     Checksum - 
     NamespaceDeclaration -  - Microsoft.AspNetCore.Razor.Evolution.IntegrationTests.TestFiles
-        UsingStatement -  - System
+        UsingStatement - (54:2,1 [12] Usings.cshtml) - System
         UsingStatement -  - System.Threading.Tasks
         UsingStatement - (1:0,1 [15] Usings.cshtml) - System.IO
         UsingStatement - (19:1,1 [32] Usings.cshtml) - Foo = System.Text.Encoding
diff --git a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.mappings.txt b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.mappings.txt
index f8b01616c7..aa9f7524ea 100644
--- a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.mappings.txt
+++ b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_DesignTime.mappings.txt
@@ -1,35 +1,40 @@
+Source Location: (54:2,1 [12] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml)
+|using System|
+Generated Location: (178:4,0 [12] )
+|using System|
+
 Source Location: (1:0,1 [15] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml)
 |using System.IO|
-Generated Location: (232:6,0 [15] )
+Generated Location: (341:10,0 [15] )
 |using System.IO|
 
 Source Location: (19:1,1 [32] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml)
 |using Foo = System.Text.Encoding|
-Generated Location: (363:11,0 [32] )
+Generated Location: (472:15,0 [32] )
 |using Foo = System.Text.Encoding|
 
 Source Location: (71:4,1 [19] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml)
 |using static System|
-Generated Location: (511:16,0 [19] )
+Generated Location: (620:20,0 [19] )
 |using static System|
 
 Source Location: (93:5,1 [27] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml)
 |using static System.Console|
-Generated Location: (646:21,0 [27] )
+Generated Location: (755:25,0 [27] )
 |using static System.Console|
 
 Source Location: (123:6,1 [41] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml)
 |using static global::System.Text.Encoding|
-Generated Location: (789:26,0 [41] )
+Generated Location: (898:30,0 [41] )
 |using static global::System.Text.Encoding|
 
 Source Location: (197:8,29 [21] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml)
 |typeof(Path).FullName|
-Generated Location: (1381:41,29 [21] )
+Generated Location: (1490:45,29 [21] )
 |typeof(Path).FullName|
 
 Source Location: (259:9,35 [20] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml)
 |typeof(Foo).FullName|
-Generated Location: (1554:46,35 [20] )
+Generated Location: (1663:50,35 [20] )
 |typeof(Foo).FullName|
 
diff --git a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_Runtime.codegen.cs b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_Runtime.codegen.cs
index 24c67f7d49..fea35df114 100644
--- a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_Runtime.codegen.cs
+++ b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_Runtime.codegen.cs
@@ -2,7 +2,11 @@
 namespace Microsoft.AspNetCore.Razor.Evolution.IntegrationTests.TestFiles
 {
     #line hidden
-    using System;
+#line 3 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml"
+using System;
+
+#line default
+#line hidden
     using System.Threading.Tasks;
 #line 1 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings.cshtml"
 using System.IO;
diff --git a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_Runtime.ir.txt b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_Runtime.ir.txt
index e765020b76..525b978c04 100644
--- a/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_Runtime.ir.txt
+++ b/test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/Usings_Runtime.ir.txt
@@ -1,7 +1,7 @@
 Document - 
     Checksum - 
     NamespaceDeclaration -  - Microsoft.AspNetCore.Razor.Evolution.IntegrationTests.TestFiles
-        UsingStatement -  - System
+        UsingStatement - (54:2,1 [14] Usings.cshtml) - System
         UsingStatement -  - System.Threading.Tasks
         UsingStatement - (1:0,1 [17] Usings.cshtml) - System.IO
         UsingStatement - (19:1,1 [34] Usings.cshtml) - Foo = System.Text.Encoding