diff --git a/OpenRA.Mods.Cnc/OpenRA.Mods.Cnc.csproj b/OpenRA.Mods.Cnc/OpenRA.Mods.Cnc.csproj
index 8aa16bc425..cd5b6fd65c 100644
--- a/OpenRA.Mods.Cnc/OpenRA.Mods.Cnc.csproj
+++ b/OpenRA.Mods.Cnc/OpenRA.Mods.Cnc.csproj
@@ -190,17 +190,17 @@
       SourceFiles="$(TargetPath)"
       DestinationFolder="$(SolutionDir)mods/common/"/>
     <!--
-        We need to copy OpenRA.Mods.Cnc.pdb (not `.dll.pdb`). This is only necessary on Windows.
-        Mono outputs a `.dll.mdb` so we can just append `.mdb` directly.
+      csc generates .pdb symbol files (not `.dll.pdb`).
+      mcs generates .dll.mdb symbol files.
     -->
     <Copy
       SourceFiles="$(TargetDir)$(TargetName).pdb"
       DestinationFolder="$(SolutionDir)mods/common/"
-      Condition="'$(OS)' == 'Windows_NT'"/>
+      Condition="Exists('$(TargetDir)$(TargetName).pdb')"/>
     <Copy
       SourceFiles="$(TargetPath).mdb"
       DestinationFolder="$(SolutionDir)mods/common/"
-      Condition="'$(OS)' == 'Unix'"/>
+      Condition="Exists('$(TargetPath).mdb')"/>
     <!-- Uncomment these lines when debugging or adding to this target
     <Message Text="DEBUG OS:                     $(OS)"/>
     <Message Text="DEBUG SolutionDir:            $(SolutionDir)"/>
diff --git a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
index a1e83aa8f9..91715fca31 100644
--- a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
+++ b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
@@ -823,17 +823,17 @@
       SourceFiles="$(TargetPath)"
       DestinationFolder="$(SolutionDir)mods/common/"/>
     <!--
-        We need to copy OpenRA.Mods.Common.pdb (not `.dll.pdb`). This is only necessary on Windows.
-        Mono outputs a `.dll.mdb` so we can just append `.mdb` directly.
+      csc generates .pdb symbol files (not `.dll.pdb`).
+      mcs generates .dll.mdb symbol files.
     -->
     <Copy
       SourceFiles="$(TargetDir)$(TargetName).pdb"
       DestinationFolder="$(SolutionDir)mods/common/"
-      Condition="'$(OS)' == 'Windows_NT'"/>
+      Condition="Exists('$(TargetDir)$(TargetName).pdb')"/>
     <Copy
       SourceFiles="$(TargetPath).mdb"
       DestinationFolder="$(SolutionDir)mods/common/"
-      Condition="'$(OS)' == 'Unix'"/>
+      Condition="Exists('$(TargetPath).mdb')"/>
     <!-- Uncomment these lines when debugging or adding to this target
     <Message Text="DEBUG OS:                     $(OS)"/>
     <Message Text="DEBUG SolutionDir:            $(SolutionDir)"/>
diff --git a/OpenRA.Mods.D2k/OpenRA.Mods.D2k.csproj b/OpenRA.Mods.D2k/OpenRA.Mods.D2k.csproj
index 6028f6ca67..8087fcc495 100644
--- a/OpenRA.Mods.D2k/OpenRA.Mods.D2k.csproj
+++ b/OpenRA.Mods.D2k/OpenRA.Mods.D2k.csproj
@@ -130,17 +130,17 @@ cd "$(SolutionDir)"</PostBuildEvent>
       SourceFiles="$(TargetPath)"
       DestinationFolder="$(SolutionDir)mods/d2k/"/>
     <!--
-        We need to copy OpenRA.Mods.D2k.pdb (not `.dll.pdb`). This is only necessary on Windows.
-        Mono outputs a `.dll.mdb` so we can just append `.mdb` directly.
+      csc generates .pdb symbol files (not `.dll.pdb`).
+      mcs generates .dll.mdb symbol files.
     -->
     <Copy
       SourceFiles="$(TargetDir)$(TargetName).pdb"
       DestinationFolder="$(SolutionDir)mods/d2k/"
-      Condition="'$(OS)' == 'Windows_NT'"/>
+      Condition="Exists('$(TargetDir)$(TargetName).pdb')"/>
     <Copy
       SourceFiles="$(TargetPath).mdb"
       DestinationFolder="$(SolutionDir)mods/d2k/"
-      Condition="'$(OS)' == 'Unix'"/>
+      Condition="Exists('$(TargetPath).mdb')"/>
     <!-- Uncomment these lines when debugging or adding to this target
     <Message Text="DEBUG OS:                     $(OS)"/>
     <Message Text="DEBUG SolutionDir:            $(SolutionDir)"/>