diff --git a/dlls/wintrust/crypt.c b/dlls/wintrust/crypt.c
index c919eef3c6a..8819ea8bb20 100644
--- a/dlls/wintrust/crypt.c
+++ b/dlls/wintrust/crypt.c
@@ -51,7 +51,14 @@ BOOL WINAPI CryptCATAdminAcquireContext(HCATADMIN* catAdmin,
 {
     FIXME("%p %s %x\n", catAdmin, debugstr_guid(sysSystem), dwFlags);
 
-    if (catAdmin) *catAdmin = (HCATADMIN)0xdeadbeef;
+    if (!catAdmin)
+    {
+        SetLastError(ERROR_INVALID_PARAMETER);
+        return FALSE;
+    }
+
+    *catAdmin = (HCATADMIN)0xdeadbeef;
+
     return TRUE;
 }
 
diff --git a/dlls/wintrust/tests/crypt.c b/dlls/wintrust/tests/crypt.c
index 887d57a7af5..31d8b8ba5ac 100644
--- a/dlls/wintrust/tests/crypt.c
+++ b/dlls/wintrust/tests/crypt.c
@@ -67,12 +67,9 @@ static void test_context(void)
     /* All NULL */
     SetLastError(0xdeadbeef);
     ret = pCryptCATAdminAcquireContext(NULL, NULL, 0);
-    todo_wine
-    {
     ok(!ret, "Expected failure\n");
     ok(GetLastError() == ERROR_INVALID_PARAMETER,
        "Expected ERROR_INVALID_PARAMETER, got %d\n", GetLastError());
-    }
 
     /* NULL GUID */
     SetLastError(0xdeadbeef);
@@ -113,12 +110,9 @@ static void test_context(void)
     /* NULL context handle and dummy GUID */
     SetLastError(0xdeadbeef);
     ret = pCryptCATAdminAcquireContext(NULL, &dummy, 0);
-    todo_wine
-    {
     ok(!ret, "Expected failure\n");
     ok(GetLastError() == ERROR_INVALID_PARAMETER,
        "Expected ERROR_INVALID_PARAMETER, got %d\n", GetLastError());
-    }
 
     /* Correct context handle and dummy GUID */
     SetLastError(0xdeadbeef);