diff --git a/drm/DrmMode.cpp b/drm/DrmMode.cpp
index dd25758..c714458 100644
--- a/drm/DrmMode.cpp
+++ b/drm/DrmMode.cpp
@@ -121,7 +121,7 @@
 
 float DrmMode::v_refresh() const {
   // Always recalculate refresh to report correct float rate
-  return clock_ / (float)(v_total_ * h_total_) * 1000.0F;
+  return static_cast<float>(clock_) / (float)(v_total_ * h_total_) * 1000.0F;
 }
 
 uint32_t DrmMode::flags() const {