diff --git a/src/Pipeline/SpirvShader.cpp b/src/Pipeline/SpirvShader.cpp
index 0df1cfd..2257017 100644
--- a/src/Pipeline/SpirvShader.cpp
+++ b/src/Pipeline/SpirvShader.cpp
@@ -442,7 +442,8 @@
 					UNSUPPORTED("SPIR-V Extension: %s", name);
 					break;
 				}
-				extensions.emplace(id, ext);
+				extensionsByID.emplace(id, ext);
+				extensionsImported.emplace(ext.name);
 				break;
 			}
 			case spv::OpName:
diff --git a/src/Pipeline/SpirvShader.hpp b/src/Pipeline/SpirvShader.hpp
index d46f760..1274909 100644
--- a/src/Pipeline/SpirvShader.hpp
+++ b/src/Pipeline/SpirvShader.hpp
@@ -748,7 +748,8 @@
 	HandleMap<Object> defs;
 	HandleMap<Function> functions;
 	std::unordered_map<StringID, String> strings;
-	HandleMap<Extension> extensions;
+	HandleMap<Extension> extensionsByID;
+	std::unordered_set<Extension::Name> extensionsImported;
 	Function::ID entryPoint;
 
 	const bool robustBufferAccess = true;
@@ -1031,8 +1032,8 @@
 
 	Extension const &getExtension(Extension::ID id) const
 	{
-		auto it = extensions.find(id);
-		ASSERT_MSG(it != extensions.end(), "Unknown extension %d", id.value());
+		auto it = extensionsByID.find(id);
+		ASSERT_MSG(it != extensionsByID.end(), "Unknown extension %d", id.value());
 		return it->second;
 	}