diff --git a/src/hmd.h b/src/hmd.h
index 6a6881977..d2360ed29 100644
--- a/src/hmd.h
+++ b/src/hmd.h
@@ -48,7 +48,7 @@ namespace bgfx
 		virtual void updateInput(HMD& _hmd) = 0;
 		virtual void recenter() = 0;
 
-		virtual bool createSwapChain(const VRDesc& _desc, int _msaaSamples, int _mirrorWidth, int _mirrorHeight);
+		virtual bool createSwapChain(const VRDesc& _desc, int _msaaSamples, int _mirrorWidth, int _mirrorHeight) = 0;
 		virtual void destroySwapChain() = 0;
 		virtual void destroyMirror() = 0;
 		virtual void makeRenderTargetActive(const VRDesc& _desc) = 0;