diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index d7d513e..0bcaa83 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -51,7 +51,7 @@ copyParamList(ParamListInfo from)
 	retval->parserSetup = NULL;
 	retval->parserSetupArg = NULL;
 	retval->numParams = from->numParams;
-	retval->paramMask = NULL;
+	retval->paramMask = from->paramMask;
 
 	for (i = 0; i < from->numParams; i++)
 	{