diff --git a/dlls/crypt32/msg.c b/dlls/crypt32/msg.c
index 15fbbc92766..2d19736dec2 100644
--- a/dlls/crypt32/msg.c
+++ b/dlls/crypt32/msg.c
@@ -1800,6 +1800,9 @@ static DWORD CRYPT_SizeOfAttributes(const CRYPT_ATTRIBUTES *attr)
         for (j = 0; j < attr->rgAttr[i].cValue; j++)
             size += attr->rgAttr[i].rgValue[j].cbData;
     }
+    /* align pointer again to be conservative */
+    if (size % sizeof(DWORD_PTR))
+        size += size % sizeof(DWORD_PTR);
     return size;
 }