diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h
index 9d568dca..227dd9bb 100644
--- a/include/fmt/format-inl.h
+++ b/include/fmt/format-inl.h
@@ -36,7 +36,7 @@ FMT_BEGIN_NAMESPACE
 FMT_FUNC void assert_fail(const char* file, int line, const char* message) {
   // Use unchecked std::fprintf to avoid triggering another assertion when
   // writing to stderr fails.
-  fprintf(stderr, "%s:%d: assertion failed: %s", file, line, message);
+  std::fprintf(stderr, "%s:%d: assertion failed: %s", file, line, message);
   abort();
 }
 #endif