diff --git a/Source/Plugins/Plugin_VideoDX9/Src/VertexManager.cpp b/Source/Plugins/Plugin_VideoDX9/Src/VertexManager.cpp
index 1fef478707..c0a9efa902 100644
--- a/Source/Plugins/Plugin_VideoDX9/Src/VertexManager.cpp
+++ b/Source/Plugins/Plugin_VideoDX9/Src/VertexManager.cpp
@@ -173,7 +173,9 @@ void VertexManager::vFlush()
 
 	Draw(stride);
 
-	if (bpmem.dstalpha.enable && bpmem.blendmode.alphaupdate)
+	bool useDstAlpha = bpmem.dstalpha.enable && bpmem.blendmode.alphaupdate &&
+						bpmem.zcontrol.pixel_format == PIXELFMT_RGBA6_Z24;
+	if (useDstAlpha)
 	{
 		DWORD write = 0;
 		if (!PixelShaderCache::SetShader(DSTALPHA_ALPHA_PASS, g_nativeVertexFmt->m_components))