diff --git a/test cases/frameworks/8 flex/lexer.l b/test cases/frameworks/8 flex/lexer.l
index 85293b2aa..952eeea12 100644
--- a/test cases/frameworks/8 flex/lexer.l	
+++ b/test cases/frameworks/8 flex/lexer.l	
@@ -1,6 +1,9 @@
 %{
 #include <stdlib.h>
 #include "parser.tab.h"
+
+extern int yylex(void);
+extern int yyerror(); 
 %}
 
 %% 
diff --git a/test cases/frameworks/8 flex/parser.y b/test cases/frameworks/8 flex/parser.y
index ff8754f32..663f2f3cf 100644
--- a/test cases/frameworks/8 flex/parser.y	
+++ b/test cases/frameworks/8 flex/parser.y	
@@ -1,3 +1,8 @@
+%{
+extern int yylex(void);
+extern int yyerror();
+%}
+
 %token BOOLEAN
 
 %%