diff --git a/recursive_compiler.c b/recursive_compiler.c
--- a/recursive_compiler.c
+++ b/recursive_compiler.c
@@ -3,8 +3,8 @@
  * Adapted from: http://de.wikipedia.org/wiki/Compiler
  */
 
+#include <stdio.h>
 #include <stdlib.h>
-#include <stdio.h>
 #include <string.h>
 
 #define MODE_POSTFIX   0
@@ -110,5 +110,5 @@
     lookahead = *expression;
     expr ();
 
-    return 0;
+    return EXIT_SUCCESS;
 }