diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5ac68d7ac5..d25f029486 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -448,8 +448,9 @@ if (FILAMENT_SUPPORTS_METAL)
     set(MATC_API_FLAGS ${MATC_API_FLAGS} -a metal)
 endif()
 
+# Disable optimizations and enable debug info (preserves names in SPIR-V)
 if (FILAMENT_DISABLE_MATOPT)
-    set(MATC_OPT_FLAGS -g)
+    set(MATC_OPT_FLAGS -gd)
 endif()
 
 set(MATC_BASE_FLAGS ${MATC_API_FLAGS} -p ${MATC_TARGET} ${MATC_OPT_FLAGS})
diff --git a/libs/gltfio/src/MaterialGenerator.cpp b/libs/gltfio/src/MaterialGenerator.cpp
index b9b1d1d1a4..54df0d9380 100644
--- a/libs/gltfio/src/MaterialGenerator.cpp
+++ b/libs/gltfio/src/MaterialGenerator.cpp
@@ -325,6 +325,7 @@ static Material* createMaterial(Engine* engine, const MaterialKey& config, const
 
     if (!optimizeShaders) {
         builder.optimization(MaterialBuilder::Optimization::NONE);
+        builder.generateDebugInfo(true);
     }
 
     static_assert(std::tuple_size<UvMap>::value == 8, "Badly sized uvset.");