diff --git a/gfx/thebes/gfxAndroidPlatform.cpp b/gfx/thebes/gfxAndroidPlatform.cpp
index 90e9d6487d3c..bf889c0f2e86 100644
--- a/gfx/thebes/gfxAndroidPlatform.cpp
+++ b/gfx/thebes/gfxAndroidPlatform.cpp
@@ -487,12 +487,12 @@ private:
 already_AddRefed<mozilla::gfx::VsyncSource>
 gfxAndroidPlatform::CreateHardwareVsyncSource()
 {
-    // Only enable true hardware vsync on kit-kat due to L HwcComposer issues
-    // Jelly Bean has inaccurate hardware vsync so disable on JB
-    // Android pre-JB doesn't have hardware vsync
-    // Once L HwcComposer issues have been resolved, re-enable for L devices
-    // L is andriod version 21, Kit-kat is 19, 20 is kit-kat for wearables
-#if defined(MOZ_WIDGET_GONK) && (ANDROID_VERSION == 19)
+    // Only enable true hardware vsync on kit-kat and L device. Jelly Bean has
+    // inaccurate hardware vsync so disable on JB. Android pre-JB doesn't have
+    // hardware vsync.
+    // L is android version 21, L-MR1 is 22, kit-kat is 19, 20 is kit-kat for
+    // wearables.
+#if defined(MOZ_WIDGET_GONK) && (ANDROID_VERSION == 19 || ANDROID_VERSION >= 21)
     nsRefPtr<GonkVsyncSource> vsyncSource = new GonkVsyncSource();
     VsyncSource::Display& display = vsyncSource->GetGlobalDisplay();
     display.EnableVsync();
diff --git a/widget/gonk/HwcComposer2D.cpp b/widget/gonk/HwcComposer2D.cpp
index d66621db6620..1f42dcc41f56 100644
--- a/widget/gonk/HwcComposer2D.cpp
+++ b/widget/gonk/HwcComposer2D.cpp
@@ -177,7 +177,9 @@ HwcComposer2D::GetInstance()
 bool
 HwcComposer2D::EnableVsync(bool aEnable)
 {
-#if ANDROID_VERSION >= 17
+    // Only support hardware vsync on kitkat, L and up due to inaccurate timings
+    // with JellyBean.
+#if (ANDROID_VERSION == 19 || ANDROID_VERSION >= 21)
     MOZ_ASSERT(NS_IsMainThread());
     if (!mHasHWVsync) {
       return false;
@@ -208,9 +210,9 @@ HwcComposer2D::RegisterHwcEventCallback()
     device->eventControl(device, HWC_DISPLAY_PRIMARY, HWC_EVENT_VSYNC, false);
     device->registerProcs(device, &sHWCProcs);
 
-// Only support actual hardware vsync on kitkat due to innaccurate timings
-// with JellyBean, and HwcComposer bugs with L. Reenable for L later
-#if ANDROID_VERSION == 19
+    // Only support hardware vsync on kitkat, L and up due to inaccurate timings
+    // with JellyBean.
+#if (ANDROID_VERSION == 19 || ANDROID_VERSION >= 21)
     mHasHWVsync = gfxPrefs::HardwareVsyncEnabled();
 #else
     mHasHWVsync = false;
@@ -221,8 +223,15 @@ HwcComposer2D::RegisterHwcEventCallback()
 void
 HwcComposer2D::Vsync(int aDisplay, nsecs_t aVsyncTimestamp)
 {
+    // Only support hardware vsync on kitkat, L and up due to inaccurate timings
+    // with JellyBean.
+#if (ANDROID_VERSION == 19 || ANDROID_VERSION >= 21)
     TimeStamp vsyncTime = mozilla::TimeStamp::FromSystemTime(aVsyncTimestamp);
     gfxPlatform::GetPlatform()->GetHardwareVsync()->GetGlobalDisplay().NotifyVsync(vsyncTime);
+#else
+    // If this device doesn't support vsync, this function should not be used.
+    MOZ_ASSERT(false);
+#endif
 }
 
 // Called on the "invalidator" thread (run from HAL).