fix English grammar
diff --git a/src/event/ngx_event_busy_lock.h b/src/event/ngx_event_busy_lock.h
index 5b50be6..3e76770 100644
--- a/src/event/ngx_event_busy_lock.h
+++ b/src/event/ngx_event_busy_lock.h
@@ -34,7 +34,7 @@
 typedef struct {
     u_char                     *md5_mask;
     char                       *md5;
-    ngx_uint_t                  cachable;
+    ngx_uint_t                  cacheable;
 
     ngx_uint_t                  busy;
     ngx_uint_t                  max_busy;
@@ -53,7 +53,7 @@
 
 ngx_int_t ngx_event_busy_lock(ngx_event_busy_lock_t *bl,
     ngx_event_busy_lock_ctx_t *ctx);
-ngx_int_t ngx_event_busy_lock_cachable(ngx_event_busy_lock_t *bl,
+ngx_int_t ngx_event_busy_lock_cacheable(ngx_event_busy_lock_t *bl,
     ngx_event_busy_lock_ctx_t *ctx);
 void ngx_event_busy_unlock(ngx_event_busy_lock_t *bl,
     ngx_event_busy_lock_ctx_t *ctx);