diff --git a/.azure/pipelines/ci.yml b/.azure/pipelines/ci.yml
index eb38671015..ae190ceefd 100644
--- a/.azure/pipelines/ci.yml
+++ b/.azure/pipelines/ci.yml
@@ -56,7 +56,7 @@ variables:
   - group: DotNet-HelixApi-Access
   - name: _UseHelixOpenQueues
     value: 'false'
-  - ${{ if ne(variables['Build.Reason'], 'PullRequest') }}:
+  - ${{ if notin(variables['Build.Reason'], 'PullRequest') }}:
     # DotNet-Blob-Feed provides: dotnetfeed-storage-access-key-1
     # Publish-Build-Assets provides: MaestroAccessToken, BotAccount-dotnet-maestro-bot-PAT
     - group: DotNet-Blob-Feed
@@ -76,7 +76,7 @@ variables:
              /p:DotNetPublishToBlobFeed=$(_DotNetPublishToBlobFeed)
              /p:DotNetPublishUsingPipelines=$(_PublishUsingPipelines)
              /p:DotNetArtifactsCategory=$(_DotNetArtifactsCategory)
-  - ${{ if eq(variables['Build.Reason'], 'PullRequest') }}:
+  - ${{ if in(variables['Build.Reason'], 'PullRequest') }}:
     - name: _BuildArgs
       value: ''
     - name: _SignType
@@ -123,10 +123,10 @@ stages:
       agentOs: Windows
       steps:
       - script: "echo ##vso[build.addbuildtag]daily-build"
-        condition: and(ne(variables['Build.Reason'], 'PullRequest'), notin(variables['DotNetFinalVersionKind'], 'release', 'prerelease'))
+        condition: and(notin(variables['Build.Reason'], 'PullRequest'), notin(variables['DotNetFinalVersionKind'], 'release', 'prerelease'))
         displayName: 'Set CI tags'
       - script: "echo ##vso[build.addbuildtag]release-candidate"
-        condition: and(ne(variables['Build.Reason'], 'PullRequest'), in(variables['DotNetFinalVersionKind'], 'release', 'prerelease'))
+        condition: and(notin(variables['Build.Reason'], 'PullRequest'), in(variables['DotNetFinalVersionKind'], 'release', 'prerelease'))
         displayName: 'Set CI tags'
 
       # !!! NOTE !!! Some of these steps have disabled code signing.
@@ -633,7 +633,7 @@ stages:
   # Helix x64
   - template: jobs/default-build.yml
     parameters:
-      condition: eq(variables['Build.Reason'], 'PullRequest')
+      condition: in(variables['Build.Reason'], 'PullRequest')
       jobName: Helix_x64
       jobDisplayName: 'Tests: Helix x64'
       agentOs: Windows
@@ -657,7 +657,7 @@ stages:
 
   - template: jobs/default-build.yml
     parameters:
-      condition: ne(variables['Build.Reason'], 'PullRequest')
+      condition: notin(variables['Build.Reason'], 'PullRequest')
       jobName: Helix_x64_daily
       jobDisplayName: 'Tests: Helix x64 Daily'
       agentOs: Windows
@@ -683,7 +683,7 @@ stages:
   # Helix ARM64
   - template: jobs/default-build.yml
     parameters:
-      condition: ne(variables['Build.Reason'], 'PullRequest')
+      condition: notin(variables['Build.Reason'], 'PullRequest')
       jobName: Helix_arm64_daily
       jobDisplayName: "Tests: Helix ARM64 Daily"
       agentOs: Linux
@@ -744,7 +744,7 @@ stages:
       displayName: Upload package artifacts
       # Only capture source build artifacts in PRs for the sake of inspecting
       # changes that impact source-build. The artifacts from this build pipeline are never actually used.
-      condition: and(succeeded(), eq(variables['Build.Reason'], 'PullRequest'))
+      condition: and(succeeded(), in(variables['Build.Reason'], 'PullRequest'))
       inputs:
         pathtoPublish: artifacts/packages/
         artifactName: Source_Build_Packages
diff --git a/.azure/pipelines/jobs/default-build.yml b/.azure/pipelines/jobs/default-build.yml
index ef4ec9e60c..f1596a7b10 100644
--- a/.azure/pipelines/jobs/default-build.yml
+++ b/.azure/pipelines/jobs/default-build.yml
@@ -89,7 +89,7 @@ jobs:
     # See https://github.com/dotnet/arcade/blob/master/Documentation/ChoosingAMachinePool.md
     pool:
       ${{ if eq(parameters.agentOs, 'macOS') }}:
-        vmImage: macOS-10.13
+        vmImage: macOS-10.14
       ${{ if eq(parameters.agentOs, 'Linux') }}:
         vmImage: ubuntu-16.04
       ${{ if eq(parameters.agentOs, 'Windows') }}:
@@ -120,9 +120,9 @@ jobs:
     - ${{ if or(ne(parameters.codeSign, true), ne(variables['System.TeamProject'], 'internal')) }}:
       - _SignType: ''
     - ${{ if and(eq(parameters.codeSign, true), eq(variables['System.TeamProject'], 'internal')) }}:
-      - ${{ if ne(variables['Build.Reason'], 'PullRequest') }}:
+      - ${{ if notin(variables['Build.Reason'], 'PullRequest') }}:
         - _SignType: real
-      - ${{ if eq(variables['Build.Reason'], 'PullRequest') }}:
+      - ${{ if in(variables['Build.Reason'], 'PullRequest') }}:
         - _SignType: test
     steps:
     - checkout: self