diff --git a/BuildTools/update-assemblyinfo.ps1 b/BuildTools/update-assemblyinfo.ps1
index f021a331d..9350425f3 100644
--- a/BuildTools/update-assemblyinfo.ps1
+++ b/BuildTools/update-assemblyinfo.ps1
@@ -53,7 +53,7 @@ function gitCommitHash() {
     if (No-Git) {
         return "0000000000000000000000000000000000000000";
     }
-    return (git rev-list "$baseCommit..HEAD") | Select -First 1;
+    return (git rev-list --max-count 1 HEAD);
 }
 
 function gitBranch() {
@@ -150,7 +150,7 @@ try {
         $out = $out.Replace('$INSERTVERSIONNAMEPOSTFIX$', $postfixVersionName);
         $out = $out.Replace('$INSERTBUILDCONFIG$', $buildConfig);
 
-        if (((Get-Content $file.Input) -Join [System.Environment]::NewLine) -ne $out) {
+        if (((Get-Content $file.Output) -Join [System.Environment]::NewLine) -ne $out) {
             $out | Out-File -Encoding utf8 $file.Output;
         }
     }
@@ -174,7 +174,7 @@ try {
 			$out = $out.Replace('$INSERTVERSIONNAMEPOSTFIX$', $postfixVersionName);
 			$out = $out.Replace('$INSERTBUILDCONFIG$', $buildConfig);
 
-			if (((Get-Content $file.Input) -Join [System.Environment]::NewLine) -ne $out) {
+			if (((Get-Content $file.Output) -Join [System.Environment]::NewLine) -ne $out) {
 				$out | Out-File -Encoding utf8 $file.Output;
 			}
 		}
diff --git a/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj b/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj
index 59445b080..b8ae5a34d 100644
--- a/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj
+++ b/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj
@@ -640,13 +640,25 @@
   </ItemGroup>
 
   <Target Name="ILSpyUpdateAssemblyInfo" BeforeTargets="BeforeBuild">
+    <ItemGroup>
+      <UpdateAssemblyInfoStamp Include="obj\update-assemblyinfo-last-commit-hash.txt" />
+    </ItemGroup>
     <PropertyGroup Condition=" '$(OS)' == 'Windows_NT' ">
       <UpdateAssemblyInfo>powershell -NoProfile -ExecutionPolicy Bypass -File BuildTools/update-assemblyinfo.ps1 $(Configuration)</UpdateAssemblyInfo>
+      <GitRevParse>git rev-parse HEAD^^{commit}</GitRevParse>
     </PropertyGroup>
     <PropertyGroup Condition=" '$(OS)' != 'Windows_NT' ">
       <UpdateAssemblyInfo>pwsh -NoProfile -ExecutionPolicy Bypass -File BuildTools/update-assemblyinfo.ps1 $(Configuration)</UpdateAssemblyInfo>
+      <GitRevParse>git rev-parse HEAD^{commit}</GitRevParse>
     </PropertyGroup>
-    <Exec WorkingDirectory=".." Command="$(UpdateAssemblyInfo)" Timeout="60000" />
+    <ReadLinesFromFile ContinueOnError="true" File="@(UpdateAssemblyInfoStamp)">
+      <Output TaskParameter="Lines" PropertyName="LastCommitHash" />
+    </ReadLinesFromFile>
+    <Exec ContinueOnError="true" WorkingDirectory=".." Command="$(GitRevParse)" ConsoleToMSBuild="true">
+      <Output TaskParameter="ConsoleOutput" PropertyName="CommitHash" />
+    </Exec>
+    <Exec WorkingDirectory=".." Command="$(UpdateAssemblyInfo)" Timeout="60000" Condition="'$(CommitHash)'!='$(LastCommitHash)'" />
+    <WriteLinesToFile Lines="$(CommitHash)" File="@(UpdateAssemblyInfoStamp)" Overwrite="true" Condition="'$(CommitHash)'!='$(LastCommitHash)'" />
   </Target>
   
 </Project>
\ No newline at end of file