diff --git a/src/iomux_impl.c b/src/iomux_impl.c
index 2f41aa6..653a839 100644
--- a/src/iomux_impl.c
+++ b/src/iomux_impl.c
@@ -53,7 +53,9 @@ void iomux_delete(struct IOMux *mux)
 }
 
 //convert the difference between future and now
-static inline void future_to_interval(struct timeval *future, const struct timeval *now, struct timeval *result)
+static inline void future_to_interval(const struct timeval *future, 
+                                      const struct timeval *now, 
+                                      struct timeval *result)
 {
     if (timercmp(future, now, >)) {
         timersub(future, now, result);