diff --git a/dlls/msdmo/dmoreg.c b/dlls/msdmo/dmoreg.c
index 864cb859e60..1c06bbfe16b 100644
--- a/dlls/msdmo/dmoreg.c
+++ b/dlls/msdmo/dmoreg.c
@@ -530,7 +530,7 @@ static HRESULT WINAPI IEnumDMO_fnNext(
 
     TRACE("(%p)->(%d %p %p %p)\n", This, cItemsToFetch, pCLSID, Names, pcItemsFetched);
 
-    if (!pCLSID || !Names)
+    if (!pCLSID)
         return E_POINTER;
 
     if (!pcItemsFetched && cItemsToFetch > 1)
@@ -656,14 +656,17 @@ static HRESULT WINAPI IEnumDMO_fnNext(
         }
 
         /* Media object wasn't filtered so add it to return list */
-        Names[count] = NULL;
         len = MAX_PATH * sizeof(WCHAR);
         ret = RegQueryValueExW(hkey, NULL, NULL, NULL, (LPBYTE)szValue, &len);
-        if (ERROR_SUCCESS == ret)
+        if (Names)
         {
-            Names[count] = CoTaskMemAlloc((strlenW(szValue) + 1) * sizeof(WCHAR));
-            if (Names[count])
-                strcpyW(Names[count], szValue);
+            Names[count] = NULL;
+            if (ret == ERROR_SUCCESS)
+            {
+                Names[count] = CoTaskMemAlloc((strlenW(szValue) + 1) * sizeof(WCHAR));
+                if (Names[count])
+                    strcpyW(Names[count], szValue);
+            }
         }
         wsprintfW(szGuidKey,szToGuidFmt,szNextKey);
         CLSIDFromString(szGuidKey, &pCLSID[count]);
diff --git a/dlls/msdmo/tests/msdmo.c b/dlls/msdmo/tests/msdmo.c
index 7617123aa52..68de11f21ab 100644
--- a/dlls/msdmo/tests/msdmo.c
+++ b/dlls/msdmo/tests/msdmo.c
@@ -107,6 +107,13 @@ static void test_DMOEnum(void)
     ok(hr == S_FALSE, "expected S_FALSE, got %#x\n", hr);
     ok(count == 0, "expected 0, got %d\n", count);
 
+    hr = IEnumDMO_Next(enum_dmo, 2, NULL, &name, &count);
+    ok(hr == E_POINTER, "expected S_FALSE, got %#x\n", hr);
+
+    hr = IEnumDMO_Next(enum_dmo, 2, &clsid, NULL, &count);
+    ok(hr == S_FALSE, "expected S_FALSE, got %#x\n", hr);
+    ok(count == 0, "expected 0, got %d\n", count);
+
     IEnumDMO_Release(enum_dmo);
 }