diff --git a/libc/include/sys/types.h b/libc/include/sys/types.h
index 8780996..5340585 100644
--- a/libc/include/sys/types.h
+++ b/libc/include/sys/types.h
@@ -111,7 +111,13 @@
 typedef  .... pthread_t;
 #endif
 
+#if !defined(__LP64__)
+/* This historical accident means that we had a signed socklen_t on 32-bit architectures. */
+typedef __int32_t __socklen_t;
+#else
+/* LP64 still has a 32-bit socklen_t. */
 typedef __uint32_t __socklen_t;
+#endif
 typedef __socklen_t socklen_t;
 
 typedef __builtin_va_list __va_list;