diff --git a/ext/fiddle/function.c b/ext/fiddle/function.c
index 45bcb50cdd..bbd73e0f0a 100644
--- a/ext/fiddle/function.c
+++ b/ext/fiddle/function.c
@@ -113,7 +113,7 @@ initialize(int argc, VALUE argv[], VALUE self)
     Check_Max_Args("args", len);
     ary = rb_ary_subseq(args, 0, len);
     for (i = 0; i < RARRAY_LEN(args); i++) {
-	VALUE a = RARRAY_AREF(args, i);
+        VALUE a = RARRAY_AREF(args, i);
 	int type = NUM2INT(a);
 	(void)INT2FFI_TYPE(type); /* raise */
 	if (INT2FIX(type) != a) rb_ary_store(ary, i, INT2FIX(type));