diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index 5eb097bd..7c97e8bd 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -366,7 +366,7 @@ spv::BuiltIn TGlslangToSpvTraverser::TranslateBuiltInDecoration(glslang::TBuiltI
         return spv::BuiltInCullDistance;
 
     case glslang::EbvViewportIndex:
-        // TODO: builder.addCapability(spv::CapabilityMultiViewport);
+        builder.addCapability(spv::CapabilityMultiViewport);
         return spv::BuiltInViewportIndex;
 
     case glslang::EbvSampleId: