diff --git a/vp9/common/vp9_systemdependent.h b/vp9/common/vp9_systemdependent.h
index fb8626ce5650db75da031fbe9bb221133b55bd58..7455abce3dec36bdf1d0f62ab34b58f7ff609229 100644
--- a/vp9/common/vp9_systemdependent.h
+++ b/vp9/common/vp9_systemdependent.h
@@ -34,7 +34,7 @@ void vpx_reset_mmx_state(void);
 
 #if defined(_MSC_VER) && _MSC_VER < 1800
 // round is not defined in MSVC before VS2013.
-static int round(double x) {
+static INLINE int round(double x) {
   if (x < 0)
     return (int)ceil(x - 0.5);
   else