diff --git a/reactos/sdk/lib/cmlib/cmlib.h b/reactos/sdk/lib/cmlib/cmlib.h
index ee84f85a4d8..e49bd384627 100644
--- a/reactos/sdk/lib/cmlib/cmlib.h
+++ b/reactos/sdk/lib/cmlib/cmlib.h
@@ -576,14 +576,14 @@ USHORT
 NTAPI
 CmpCopyName(
     IN PHHIVE Hive,
-    IN PWCHAR Destination,
+    OUT PWCHAR Destination,
     IN PUNICODE_STRING Source
 );
 
 VOID
 NTAPI
 CmpCopyCompressedName(
-    IN PWCHAR Destination,
+    OUT PWCHAR Destination,
     IN ULONG DestinationLength,
     IN PWCHAR Source,
     IN ULONG SourceLength
diff --git a/reactos/sdk/lib/cmlib/cmname.c b/reactos/sdk/lib/cmlib/cmname.c
index 8dc2e4a5eeb..918cbb282dd 100644
--- a/reactos/sdk/lib/cmlib/cmname.c
+++ b/reactos/sdk/lib/cmlib/cmname.c
@@ -19,7 +19,7 @@
 USHORT
 NTAPI
 CmpCopyName(IN PHHIVE Hive,
-            IN PWCHAR Destination,
+            OUT PWCHAR Destination,
             IN PUNICODE_STRING Source)
 {
     ULONG i;
@@ -53,7 +53,7 @@ CmpCopyName(IN PHHIVE Hive,
 
 VOID
 NTAPI
-CmpCopyCompressedName(IN PWCHAR Destination,
+CmpCopyCompressedName(OUT PWCHAR Destination,
                       IN ULONG DestinationLength,
                       IN PWCHAR Source,
                       IN ULONG SourceLength)