diff --git a/ch05/5-18-dcl/parse.c b/ch05/5-18-dcl/parse.c
index b27b42a..26d137d 100644
--- a/ch05/5-18-dcl/parse.c
+++ b/ch05/5-18-dcl/parse.c
@@ -24,7 +24,7 @@ void parse() {
 }
 
 static void declaration_specifiers() {
-  while (gettoken(), STORAGE_CLASS_SPECIFIER <= tokentype && tokentype <= TYPE_QUALIFIER) {
+  while (gettoken() && STORAGE_CLASS_SPECIFIER <= tokentype && tokentype <= TYPE_QUALIFIER) {
     strcat(specifiers, tokenval);
     strcat(specifiers, " ");
   }