diff --git a/main.c b/main.c
index 03dd5a4443..5cffa24cc8 100644
--- a/main.c
+++ b/main.c
@@ -30,7 +30,7 @@
 # undef RUBY_DEBUG_ENV
 #endif
 
-int
+static int
 rb_main(int argc, char **argv)
 {
 #ifdef RUBY_DEBUG_ENV
@@ -48,11 +48,13 @@ rb_main(int argc, char **argv)
     }
 }
 
-int main(int argc, char **argv) {
+int
+main(int argc, char **argv)
+{
 #if defined(__wasm__) && !defined(__EMSCRIPTEN__)
-  int rb_wasm_rt_start(int (main)(int argc, char **argv), int argc, char **argv);
-  return rb_wasm_rt_start(rb_main, argc, argv);
+    int rb_wasm_rt_start(int (main)(int argc, char **argv), int argc, char **argv);
+    return rb_wasm_rt_start(rb_main, argc, argv);
 #else
-  return rb_main(argc, argv);
+    return rb_main(argc, argv);
 #endif
 }