diff --git a/test/tools/OpenCover/OpenCover.psm1 b/test/tools/OpenCover/OpenCover.psm1
index 5526c71dd6..60e6b7fcba 100644
--- a/test/tools/OpenCover/OpenCover.psm1
+++ b/test/tools/OpenCover/OpenCover.psm1
@@ -412,8 +412,8 @@ function Invoke-OpenCover
     }
 
     $targetArgString = $targetArgs -join " "
-    # the order seems to be important
-    $openCoverArgs = "-target:$target","-targetargs:""$targetArgString""","-register:user","-output:${outputLog}","-nodefaultfilters","-oldstyle","-hideskipped:all"
+    # the order seems to be important. Always keep -targetargs as the last parameter.
+    $openCoverArgs = "-target:$target","-register:user","-output:${outputLog}","-nodefaultfilters","-oldstyle","-hideskipped:all","-targetargs:`"$targetArgString`""
 
     if ( $PSCmdlet.ShouldProcess("$OpenCoverBin $openCoverArgs")  )
     {