diff --git a/src/parser/parser.c b/src/parser/parser.c
index ec60b71..d1f0ebc 100644
--- a/src/parser/parser.c
+++ b/src/parser/parser.c
@@ -15,7 +15,7 @@ int parser_init(void)
     if (state == PARSER_STATE_READY)
     {
         perror("Internal error: tried to initialize the parser module twice.");
-        return NULL;
+        return false;
     }
     int success = grammar_init();
     if (success == false)