diff --git a/dlls/shlwapi/clist.c b/dlls/shlwapi/clist.c
index 52bee37c9e4..47bd8d7392f 100644
--- a/dlls/shlwapi/clist.c
+++ b/dlls/shlwapi/clist.c
@@ -65,7 +65,7 @@ static inline LPDATABLOCK_HEADER NextItem(LPDBLIST lpList)
  *  the call returns S_OK but does not actually add the element.
  *  See SHWriteDataBlockList.
  */
-HRESULT WINAPI SHAddDataBlock(LPDBLIST* lppList, const DATABLOCK_HEADER *lpNewItem)
+BOOL WINAPI SHAddDataBlock(LPDBLIST* lppList, const DATABLOCK_HEADER *lpNewItem)
 {
   LPDATABLOCK_HEADER lpInsertAt = NULL;
   ULONG ulSize;
@@ -73,11 +73,11 @@ HRESULT WINAPI SHAddDataBlock(LPDBLIST* lppList, const DATABLOCK_HEADER *lpNewIt
   TRACE("(%p,%p)\n", lppList, lpNewItem);
 
   if(!lppList || !lpNewItem )
-    return E_INVALIDARG;
+    return FALSE;
 
   if (lpNewItem->cbSize < sizeof(DATABLOCK_HEADER) ||
       lpNewItem->dwSignature == CLIST_ID_CONTAINER)
-    return S_OK;
+    return FALSE;
 
   ulSize = lpNewItem->cbSize;
 
@@ -134,9 +134,9 @@ HRESULT WINAPI SHAddDataBlock(LPDBLIST* lppList, const DATABLOCK_HEADER *lpNewIt
     lpInsertAt = NextItem(lpInsertAt);
     lpInsertAt->cbSize = 0;
 
-    return lpNewItem->cbSize;
+    return TRUE;
   }
-  return S_OK;
+  return FALSE;
 }
 
 /*************************************************************************
diff --git a/dlls/shlwapi/tests/clist.c b/dlls/shlwapi/tests/clist.c
index 8c63f31af7b..0c914d608e5 100644
--- a/dlls/shlwapi/tests/clist.c
+++ b/dlls/shlwapi/tests/clist.c
@@ -289,6 +289,7 @@ static void test_CList(void)
   DATABLOCK_HEADER *inserted;
   BYTE buff[64];
   unsigned int i;
+  BOOL ret;
 
   if (!pSHWriteDataBlockList || !pSHReadDataBlockList || !pSHFreeDataBlockList || !pSHAddDataBlock ||
       !pSHRemoveDataBlock || !pSHFindDataBlock)
@@ -304,10 +305,10 @@ static void test_CList(void)
     for (i = 0; i < item->cbSize; i++)
       buff[sizeof(DATABLOCK_HEADER) + i] = i * 2;
 
-    hRet = pSHAddDataBlock(&list, inserted);
-    ok(hRet > S_OK, "failed list add\n");
+    ret = pSHAddDataBlock(&list, inserted);
+    ok(ret == TRUE, "got %d\n", ret);
 
-    if (hRet > S_OK)
+    if (ret == TRUE)
     {
       ok(list && list->cbSize, "item not added\n");
 
@@ -381,10 +382,11 @@ static void test_CList(void)
   inserted->cbSize = sizeof(DATABLOCK_HEADER) - 1;
   inserted->dwSignature = 33;
 
-  /* The call succeeds but the item is not inserted, except on some early
-   * versions which return failure. Wine behaves like later versions.
-   */
-  pSHAddDataBlock(&list, inserted);
+  ret = pSHAddDataBlock(NULL, inserted);
+  ok(!ret, "got %d\n", ret);
+
+  ret = pSHAddDataBlock(&list, inserted);
+  ok(!ret, "got %d\n", ret);
 
   inserted = pSHFindDataBlock(list, 33);
   ok(inserted == NULL, "inserted bad element size\n");
@@ -393,8 +395,8 @@ static void test_CList(void)
   inserted->cbSize = 44;
   inserted->dwSignature = ~0U;
 
-  /* See comment above, some early versions fail this call */
-  pSHAddDataBlock(&list, inserted);
+  ret = pSHAddDataBlock(&list, inserted);
+  ok(!ret, "got %d\n", ret);
 
   item = clist_items;