diff --git a/dlls/advapi32/cred.c b/dlls/advapi32/cred.c
index 0afbb63786f..0c8c1298795 100644
--- a/dlls/advapi32/cred.c
+++ b/dlls/advapi32/cred.c
@@ -1821,9 +1821,6 @@ BOOL WINAPI CredWriteW(PCREDENTIALW Credential, DWORD Flags)
             SetLastError(ERROR_BAD_USERNAME);
             return FALSE;
         }
-
-        Credential->CredentialBlobSize = 0;
-        Credential->CredentialBlob = NULL;
     }
 
 #ifdef __APPLE__
diff --git a/dlls/advapi32/tests/cred.c b/dlls/advapi32/tests/cred.c
index 4d4e6c8c1b9..c2d9027e1de 100644
--- a/dlls/advapi32/tests/cred.c
+++ b/dlls/advapi32/tests/cred.c
@@ -202,7 +202,9 @@ static void check_blob(int line, DWORD cred_type, PCREDENTIALA cred)
 {
     if (cred_type == CRED_TYPE_DOMAIN_PASSWORD)
     {
+        todo_wine
         ok_(__FILE__, line)(cred->CredentialBlobSize == 0, "expected CredentialBlobSize of 0 but got %d\n", cred->CredentialBlobSize);
+        todo_wine
         ok_(__FILE__, line)(!cred->CredentialBlob, "expected NULL credentials but got %p\n", cred->CredentialBlob);
     }
     else