diff --git a/build.zig b/build.zig
index ff3eb70..0ed51ea 100644
--- a/build.zig
+++ b/build.zig
@@ -139,6 +139,6 @@ const SOURCES = .{
 };
 
 const FLAGS = .{
-    "-std=c89",
+    "-std=gnu89",
     "-D_REENTRANT",
 };