diff --git a/include/fmt/printf.h b/include/fmt/printf.h
index e25e6fba..d07d1c65 100644
--- a/include/fmt/printf.h
+++ b/include/fmt/printf.h
@@ -627,7 +627,8 @@ auto vfprintf(std::FILE* f, basic_string_view<Char> fmt,
   auto buf = basic_memory_buffer<Char>();
   detail::vprintf(buf, fmt, args);
   size_t size = buf.size();
-  return std::fwrite(buf.data(), sizeof(Char), size, f) < size
+  return std::fwrite(buf.data(), sizeof(Char), size, f) < size ||
+                 size > detail::to_unsigned(detail::max_value<int>())
              ? -1
              : static_cast<int>(size);
 }
diff --git a/src/fmt-c.cc b/src/fmt-c.cc
index aec19072..5014d694 100644
--- a/src/fmt-c.cc
+++ b/src/fmt-c.cc
@@ -8,6 +8,7 @@
 #include "fmt/fmt-c.h"
 
 #include <fmt/core.h>
+#include <limits.h>  // INT_MAX
 
 constexpr size_t max_c_format_args = 16;
 
@@ -45,6 +46,7 @@ extern "C" int fmt_vformat(char* buffer, size_t size, const char* fmt,
     auto result = fmt::vformat_to_n(
         buffer, size, fmt,
         fmt::format_args(format_args, static_cast<int>(num_args)));
+    if (result.size > INT_MAX) return fmt_error;
     return static_cast<int>(result.size);
   }
   FMT_CATCH(...) {}