diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7b71063b6..3fdbe9c44 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -123,10 +123,11 @@ if(EMSCRIPTEN)
     add_compile_options(-pthread)
     # mimalloc is needed for good performance
     add_link_options(-sMALLOC=mimalloc)
+    add_link_options(-sPTHREAD_POOL_SIZE=4)
     # The default stack size apparently causes problem when parallelization is
     # enabled.
-    add_link_options(-sSTACK_SIZE=20MB)
-    add_link_options(-sINITIAL_MEMORY=20MB)
+    add_link_options(-sSTACK_SIZE=30MB)
+    add_link_options(-sINITIAL_MEMORY=32MB)
   endif()
   if(MANIFOLD_DEBUG)
     list(APPEND MANIFOLD_FLAGS -fexceptions)
diff --git a/flake.nix b/flake.nix
index e24baafb8..ee78a62ee 100644
--- a/flake.nix
+++ b/flake.nix
@@ -125,7 +125,7 @@
             export EM_CACHE=$(pwd)/.emscriptencache
             mkdir build
             cd build
-            emcmake cmake -DCMAKE_BUILD_TYPE=Release \
+            emcmake cmake -DCMAKE_BUILD_TYPE=MinSizeRel \
             -DMANIFOLD_PAR=${if parallel then "ON" else "OFF"} \
             -DFETCHCONTENT_SOURCE_DIR_GOOGLETEST=${gtest-src} \
             -DFETCHCONTENT_SOURCE_DIR_TBB=${onetbb-src} \
diff --git a/test/test_main.cpp b/test/test_main.cpp
index 7408629b8..aca1ab65e 100644
--- a/test/test_main.cpp
+++ b/test/test_main.cpp
@@ -18,7 +18,6 @@
 #include "test.h"
 
 #if (MANIFOLD_PAR == 1)
-#include <oneapi/tbb/global_control.h>
 #include <oneapi/tbb/parallel_for.h>
 #endif
 
@@ -54,8 +53,6 @@ int main(int argc, char** argv) {
   // https://github.com/oneapi-src/oneTBB/blob/master/WASM_Support.md#limitations
 #if defined(__EMSCRIPTEN__) && (MANIFOLD_PAR == 1)
   int num_threads = tbb::this_task_arena::max_concurrency();
-  oneapi::tbb::global_control global_limit(
-      tbb::global_control::thread_stack_size, 16 * 1024 * 1024);
   std::atomic<int> barrier{num_threads};
   tbb::parallel_for(
       0, num_threads,