diff --git a/src/filter.h b/src/filter.h
index 5fa0671..9eaf2fe 100644
--- a/src/filter.h
+++ b/src/filter.h
@@ -23,12 +23,11 @@ typedef struct f2b_filter_t {
   void  (*destroy) (void *cfg);
 } f2b_filter_t;
 
-f2b_filter_t * f2b_filter_create (f2b_config_section_t *config, const char *id);
-void           f2b_filter_destroy(f2b_filter_t *b);
-
-bool f2b_filter_append(f2b_filter_t *b, const char *pattern);
-bool f2b_filter_match(f2b_filter_t *b, const char *line, char *buf, size_t buf_size);
-const char * f2b_filter_error(f2b_filter_t *b);
-void f2b_filter_stats (f2b_filter_t *b, char *res, size_t ressize);
+f2b_filter_t * f2b_filter_create  (f2b_config_section_t *config, const char *id);
+const char *   f2b_filter_error   (f2b_filter_t *f);
+bool           f2b_filter_append  (f2b_filter_t *f, const char *pattern);
+bool           f2b_filter_match   (f2b_filter_t *f, const char *line, char *buf, size_t buf_size);
+void           f2b_filter_stats   (f2b_filter_t *f, char *res, size_t ressize);
+void           f2b_filter_destroy (f2b_filter_t *f);
 
 #endif /* F2B_FILTER_H_ */