diff --git a/dlls/crypt32/tests/protectdata.c b/dlls/crypt32/tests/protectdata.c
index afe74ca..29d04e8 100644
--- a/dlls/crypt32/tests/protectdata.c
+++ b/dlls/crypt32/tests/protectdata.c
@@ -235,7 +235,7 @@
 
     res = pCryptUnprotectData(&encrypted, NULL, NULL, NULL, NULL, 0, &output);
     ok(res != 0, "can't unprotect; last error %u\n", GetLastError());
-    ok(output.cbData == strlen(plaintext), "output wrong length %d for input '%s', wanted %d\n", output.cbData, plaintext, strlen(plaintext));
+    ok(output.cbData == strlen(plaintext), "output wrong length %d for input '%s', wanted %d\n", output.cbData, plaintext, lstrlenA(plaintext));
     ok(!memcmp(plaintext, (char *)output.pbData, output.cbData), "output wrong contents for input '%s'\n", plaintext);
     LocalFree(output.pbData);
     LocalFree(encrypted.pbData);