diff --git a/dlls/wbemprox/security.c b/dlls/wbemprox/security.c
index 0ff6c0bff94..d3057e01f55 100644
--- a/dlls/wbemprox/security.c
+++ b/dlls/wbemprox/security.c
@@ -120,8 +120,11 @@ static HRESULT get_sd( SECURITY_DESCRIPTOR **sd, DWORD *size )
 
     if (SUCCEEDED(hr))
     {
-        if (!MakeSelfRelativeSD(&absolute_sd, *sd, size))
+        if (!MakeSelfRelativeSD(&absolute_sd, *sd, size)) {
+            HeapFree( GetProcessHeap(), 0, *sd );
+	    *sd = NULL;
             hr = E_FAIL;
+        }
     }
 
     return hr;