diff --git a/examples/esbuild-browser/serve.json b/examples/esbuild-browser/serve.json
index 825afee008..db8e11d4ad 100644
--- a/examples/esbuild-browser/serve.json
+++ b/examples/esbuild-browser/serve.json
@@ -3,8 +3,14 @@
     {
       "source": "*",
       "headers": [
-        { "key": "Cross-Origin-Embedder-Policy", "value": "require-corp" },
-        { "key": "Cross-Origin-Opener-Policy", "value": "same-origin" }
+        {
+          "key": "Cross-Origin-Embedder-Policy",
+          "value": "require-corp"
+        },
+        {
+          "key": "Cross-Origin-Opener-Policy",
+          "value": "same-origin"
+        }
       ]
     }
   ]
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 60a692282a..03302687b8 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -22,7 +22,7 @@ if(DEFINED ENV{DUCKDB_WASM_LOADABLE_EXTENSIONS})
 endif()
 
 
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17 -DDUCKDB_WASM=1")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17 -DDUCKDB_WASM=1 -DFSST_MUST_ALIGN")
 
 if(DUCKDB_WASM_LOADABLE_EXTENSIONS)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DWASM_LOADABLE_EXTENSIONS=1 -DDUCKDB_EXTENSION_AUTOLOAD_DEFAULT=1 -fPIC")
@@ -110,16 +110,11 @@ if(EMSCRIPTEN)
     endif()
   # Debug build
   elseif(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} \
-      --profiling \
-      -gsource-map \
-      --source-map-base=file://${CMAKE_BINARY_DIR}/")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g")
     set(WASM_LINK_FLAGS "${WASM_LINK_FLAGS} \
       -sASSERTIONS=1 \
       -sSAFE_HEAP=1 \
-      -gsource-map \
-      --source-map-base=file://${CMAKE_BINARY_DIR}/ \
-      -sSEPARATE_DWARF_URL=file://${CMAKE_BINARY_DIR}/duckdb.wasm")
+      -g")
     # ... with fast linking
     if(WASM_FAST_LINKING)
       set(WASM_LINK_FLAGS "${WASM_LINK_FLAGS} -O0")
diff --git a/packages/duckdb-wasm/src/targets/duckdb-browser-coi.pthread.worker.ts b/packages/duckdb-wasm/src/targets/duckdb-browser-coi.pthread.worker.ts
index e92933615a..2be2de22ac 100644
--- a/packages/duckdb-wasm/src/targets/duckdb-browser-coi.pthread.worker.ts
+++ b/packages/duckdb-wasm/src/targets/duckdb-browser-coi.pthread.worker.ts
@@ -12,15 +12,17 @@ for (const func of Object.getOwnPropertyNames(BROWSER_RUNTIME)) {
 // We just override the load handler of the pthread wrapper to bundle DuckDB with esbuild.
 globalThis.onmessage = (e: any) => {
     if (e.data.cmd === 'load') {
-        const m = pthread_api.getModule();
+        let m = pthread_api.getModule();
 
-        // Module and memory were sent from main thread
+        (globalThis as any).startWorker = (instance: any) => {
+            m = instance;
+            postMessage({ cmd: 'loaded' });
+        };
         m['wasmModule'] = e.data.wasmModule;
         m['wasmMemory'] = e.data.wasmMemory;
         m['buffer'] = m['wasmMemory'].buffer;
         m['ENVIRONMENT_IS_PTHREAD'] = true;
-
-        DuckDB(m).then(function (instance) {
+        DuckDB(m).then((instance: any) => {
             pthread_api.setModule(instance);
         });
     } else if (e.data.cmd === 'registerFileHandle') {