diff --git a/ee.h b/ee.h
index e689802..1fff3c1 100644
--- a/ee.h
+++ b/ee.h
@@ -25,7 +25,7 @@ double  peek(STACK);
 int     isNum(const char*);
 int     arrity(const char);
 
-double  evaluate(STACK*, int);
+double  evaluate(STACK*, char);
 double* operands(STACK*, int);
 double  fact(int n);