diff --git a/classes.c b/classes.c
index 3e487e8..a7ab8ea 100644
--- a/classes.c
+++ b/classes.c
@@ -1191,7 +1191,8 @@ int cu__for_each_class(struct cu *self,
 int cu__for_each_function(struct cu *cu,
 			  int (*iterator)(struct function *func, void *cookie),
 			  void *cookie,
-			  struct function *(*filter)(struct function *function))
+			  struct function *(*filter)(struct function *function,
+				  		     void *cookie))
 {
 
 	struct function *pos;
@@ -1199,7 +1200,7 @@ int cu__for_each_function(struct cu *cu,
 	list_for_each_entry(pos, &cu->functions, tag.node) {
 		struct function *function = pos;
 		if (filter != NULL) {
-			function = filter(pos);
+			function = filter(pos, cookie);
 			if (function == NULL)
 				continue;
 		}
diff --git a/classes.h b/classes.h
index 8b43a52..5431e4a 100644
--- a/classes.h
+++ b/classes.h
@@ -166,7 +166,8 @@ extern int	    cu__for_each_function(struct cu *cu,
 					  int (*iterator)(struct function *func,
 							  void *cookie),
 					  void *cookie,
-			struct function *(*filter)(struct function *function));
+			struct function *(*filter)(struct function *function,
+						   void *cookie));
 extern void	    cus__for_each_cu(struct cus *self,
 				     int (*iterator)(struct cu *cu,
 						     void *cookie),
diff --git a/pfunct.c b/pfunct.c
index 214a0e8..fefb684 100644
--- a/pfunct.c
+++ b/pfunct.c
@@ -175,7 +175,8 @@ static void fn_stats__chkdupdef(const struct function *self,
 		putchar('\n');
 }
 
-static struct function *function__filter(struct function *function)
+static struct function *function__filter(struct function *function,
+					 void *cookie)
 {
 	struct fn_stats *fstats;