diff --git a/reactos/drivers/wdm/audio/backpln/portcls/undoc.cpp b/reactos/drivers/wdm/audio/backpln/portcls/undoc.cpp
index 6df999f0d87..d4249be5cb2 100644
--- a/reactos/drivers/wdm/audio/backpln/portcls/undoc.cpp
+++ b/reactos/drivers/wdm/audio/backpln/portcls/undoc.cpp
@@ -207,6 +207,7 @@ PropertyItemDispatch(
     else
     {
         // invalid buffer size
+        FreeItem(PropertyRequest, TAG_PORTCLASS);
         return STATUS_INVALID_BUFFER_SIZE;
     }