diff --git a/compiler/assemble.pas b/compiler/assemble.pas
index 4047673b41..ba8b5696f7 100644
--- a/compiler/assemble.pas
+++ b/compiler/assemble.pas
@@ -297,7 +297,7 @@ Implementation
         var
           dir : TRawByteSearchRec;
         begin
-          if findfirst(s+source_info.dirsep+'*'+AExt,faAnyFile,dir) = 0 then
+          if findfirst(FixPath(s,false)+'*'+AExt,faAnyFile,dir) = 0 then
             begin
               repeat
                 DeleteFile(s+source_info.dirsep+dir.name);