diff --git a/emsdk_manifest.json b/emsdk_manifest.json
index 14e4682..7b6d89e 100644
--- a/emsdk_manifest.json
+++ b/emsdk_manifest.json
@@ -104,7 +104,7 @@
     "custom_install_script": "build_fastcomp",
     "activated_path": "%installation_dir%/%fastcomp_build_bin_dir%",
     "activated_cfg": "LLVM_ROOT='%installation_dir%/%fastcomp_build_bin_dir%'",
-    "cmake_build_type": "RelWithDebInfo"
+    "cmake_build_type": "Release"
   },
   {
     "id": "clang",
@@ -117,7 +117,7 @@
     "custom_install_script": "build_fastcomp",
     "activated_path": "%installation_dir%/%fastcomp_build_bin_dir%",
     "activated_cfg": "LLVM_ROOT='%installation_dir%/%fastcomp_build_bin_dir%'",
-    "cmake_build_type": "RelWithDebInfo"
+    "cmake_build_type": "Release"
   },
   {
     "id": "clang",
@@ -791,7 +791,7 @@
     "activated_cfg": "EMSCRIPTEN_ROOT='%installation_dir%';EMSCRIPTEN_NATIVE_OPTIMIZER='%installation_dir%%generator_prefix%_32bit_optimizer/%cmake_build_type_on_win%optimizer%.exe%'",
     "activated_path": "%installation_dir%",
     "activated_env": "EMSCRIPTEN=%installation_dir%",
-    "cmake_build_type": "RelWithDebInfo",
+    "cmake_build_type": "Release",
     "custom_install_script": "build_optimizer",
     "custom_is_installed_script": "is_optimizer_installed",
     "custom_uninstall_script": "uninstall_optimizer"
@@ -821,7 +821,7 @@
     "activated_cfg": "EMSCRIPTEN_ROOT='%installation_dir%';EMSCRIPTEN_NATIVE_OPTIMIZER='%installation_dir%%generator_prefix%_64bit_optimizer/%cmake_build_type_on_win%optimizer%.exe%'",
     "activated_path": "%installation_dir%",
     "activated_env": "EMSCRIPTEN=%installation_dir%",
-    "cmake_build_type": "RelWithDebInfo",
+    "cmake_build_type": "Release",
     "custom_install_script": "build_optimizer",
     "custom_is_installed_script": "is_optimizer_installed",
     "custom_uninstall_script": "uninstall_optimizer"