diff --git a/emcc.py b/emcc.py
index 5ebefb9b8c99b..3f590901a6c09 100755
--- a/emcc.py
+++ b/emcc.py
@@ -1739,6 +1739,9 @@ def include_and_export(name):
       # requires JS legalization
       shared.Settings.LEGALIZE_JS_FFI = 0
 
+    if shared.Settings.STANDALONE_WASM or (shared.Settings.MINIMAL_RUNTIME and not shared.Settings.USE_PTHREADS):
+      shared.Settings.MEMORY_DEFINED_IN_WASM = 1
+
     if shared.Settings.WASM_BIGINT:
       shared.Settings.LEGALIZE_JS_FFI = 0
 
diff --git a/emscripten.py b/emscripten.py
index 0fa36419622ad..39a28f8f283f2 100644
--- a/emscripten.py
+++ b/emscripten.py
@@ -536,10 +536,7 @@ def create_em_js(forwarded_json, metadata):
 
 
 def add_standard_wasm_imports(send_items_map):
-  # Normally we import these into the wasm (so that JS could use them even
-  # before the wasm loads), while in standalone mode we do not depend
-  # on JS to create them, but create them in the wasm and export them.
-  if not shared.Settings.STANDALONE_WASM:
+  if not shared.Settings.MEMORY_DEFINED_IN_WASM:
     memory_import = 'wasmMemory'
     if shared.Settings.MODULARIZE and shared.Settings.USE_PTHREADS:
       # Pthreads assign wasmMemory in their worker startup. In MODULARIZE mode, they cannot assign inside the
diff --git a/src/postamble_minimal.js b/src/postamble_minimal.js
index 03d70a2161011..4ddc50b0a3417 100644
--- a/src/postamble_minimal.js
+++ b/src/postamble_minimal.js
@@ -204,6 +204,25 @@ WebAssembly.instantiate(Module['wasm'], imports).then(function(output) {
   /*** ASM_MODULE_EXPORTS ***/
 #endif
   wasmTable = asm['__indirect_function_table'];
+#if ASSERTIONS
+  assert(wasmTable);
+#endif
+
+#if !USE_PTHREADS
+  wasmMemory = asm['memory'];
+#if ASSERTIONS
+  assert(wasmMemory);
+  assert(wasmMemory.buffer.byteLength === {{{ INITIAL_MEMORY }}});
+#endif
+  updateGlobalBufferAndViews(wasmMemory.buffer);
+#endif
+
+#if MEM_INIT_METHOD == 1 && !MEM_INIT_IN_WASM && !SINGLE_FILE
+#if ASSERTIONS
+  if (!Module['mem']) throw 'Must load memory initializer as an ArrayBuffer in to variable Module.mem before adding compiled output .js script to the DOM';
+#endif
+  HEAPU8.set(new Uint8Array(Module['mem']), {{{ GLOBAL_BASE }}});
+#endif
 
   initRuntime(asm);
 #if USE_PTHREADS && PTHREAD_POOL_SIZE
diff --git a/src/preamble_minimal.js b/src/preamble_minimal.js
index 76a4cba0c3783..edeaf789ebd72 100644
--- a/src/preamble_minimal.js
+++ b/src/preamble_minimal.js
@@ -55,52 +55,13 @@ Module['wasm'] = base64Decode('{{{ getQuoted("WASM_BINARY_DATA") }}}');
 #include "runtime_functions.js"
 #include "runtime_strings.js"
 
-#if USE_PTHREADS
-if (!ENVIRONMENT_IS_PTHREAD) {
-#endif
-
-#if ALLOW_MEMORY_GROWTH && MAXIMUM_MEMORY != -1
-var wasmMaximumMemory = {{{ MAXIMUM_MEMORY >>> 16 }}};
-#else
-var wasmMaximumMemory = {{{ INITIAL_MEMORY >>> 16}}};
-#endif
-
-var wasmMemory = new WebAssembly.Memory({
-  'initial': {{{ INITIAL_MEMORY >>> 16 }}}
-#if USE_PTHREADS || !ALLOW_MEMORY_GROWTH || MAXIMUM_MEMORY != -1
-  , 'maximum': wasmMaximumMemory
-#endif
-#if USE_PTHREADS
-  , 'shared': true
-#endif
-  });
-
-var wasmTable;
-var buffer = wasmMemory.buffer;
-
-#if USE_PTHREADS
-}
-#if ASSERTIONS
-assert(buffer instanceof SharedArrayBuffer, 'requested a shared WebAssembly.Memory but the returned buffer is not a SharedArrayBuffer, indicating that while the browser has SharedArrayBuffer it does not have WebAssembly threads support - you may need to set a flag');
-#endif
-#endif
-
-#if ASSERTIONS
-#if USE_PTHREADS
-if (!ENVIRONMENT_IS_PTHREAD) {
-#endif
-assert(buffer.byteLength === {{{ INITIAL_MEMORY }}});
-#if USE_PTHREADS
-}
-#endif
-#endif // ASSERTIONS
-
-#if ALLOW_MEMORY_GROWTH
-// In ALLOW_MEMORY_GROWTH, we need to be able to re-initialize the
-// typed array buffer and heap views to the buffer whenever the heap
-// is resized.
 var HEAP8, HEAP16, HEAP32, HEAPU8, HEAPU16, HEAPU32, HEAPF32, HEAPF64;
+var wasmMemory, buffer, wasmTable;
+
 function updateGlobalBufferAndViews(b) {
+#if ASSERTIONS && USE_PTHREADS
+  assert(b instanceof SharedArrayBuffer, 'requested a shared WebAssembly.Memory but the returned buffer is not a SharedArrayBuffer, indicating that while the browser has SharedArrayBuffer it does not have WebAssembly threads support - you may need to set a flag');
+#endif
   buffer = b;
   HEAP8 = new Int8Array(b);
   HEAP16 = new Int16Array(b);
@@ -111,33 +72,33 @@ function updateGlobalBufferAndViews(b) {
   HEAPF32 = new Float32Array(b);
   HEAPF64 = new Float64Array(b);
 }
-updateGlobalBufferAndViews(buffer);
-#else
-// In non-ALLOW_MEMORY_GROWTH scenario, we only need to initialize
-// the heap once, so optimize code size to do it statically here.
-var HEAP8 = new Int8Array(buffer);
-var HEAP16 = new Int16Array(buffer);
-var HEAP32 = new Int32Array(buffer);
-var HEAPU8 = new Uint8Array(buffer);
-var HEAPU16 = new Uint16Array(buffer);
-var HEAPU32 = new Uint32Array(buffer);
-var HEAPF32 = new Float32Array(buffer);
-var HEAPF64 = new Float64Array(buffer);
-#endif
 
-#if USE_PTHREADS && ((MEM_INIT_METHOD == 1 && !MEM_INIT_IN_WASM && !SINGLE_FILE) || USES_DYNAMIC_ALLOC)
+#if USE_PTHREADS
 if (!ENVIRONMENT_IS_PTHREAD) {
+#if ALLOW_MEMORY_GROWTH && MAXIMUM_MEMORY != -1
+  var wasmMaximumMemory = {{{ MAXIMUM_MEMORY >>> 16 }}};
+#else
+  var wasmMaximumMemory = {{{ INITIAL_MEMORY >>> 16}}};
 #endif
-
-#if MEM_INIT_METHOD == 1 && !MEM_INIT_IN_WASM && !SINGLE_FILE
-#if ASSERTIONS
-if (!Module['mem']) throw 'Must load memory initializer as an ArrayBuffer in to variable Module.mem before adding compiled output .js script to the DOM';
-#endif
-HEAPU8.set(new Uint8Array(Module['mem']), {{{ GLOBAL_BASE }}});
+  wasmMemory = new WebAssembly.Memory({
+    'initial': {{{ INITIAL_MEMORY >>> 16 }}}
+#if USE_PTHREADS || !ALLOW_MEMORY_GROWTH || MAXIMUM_MEMORY != -1
+    , 'maximum': wasmMaximumMemory
 #endif
+    , 'shared': true
+    });
+}
 
-#if USE_PTHREADS && ((MEM_INIT_METHOD == 1 && !MEM_INIT_IN_WASM && !SINGLE_FILE) || USES_DYNAMIC_ALLOC)
+#if MODULARIZE
+if (ENVIRONMENT_IS_WORKER) {
+  updateGlobalBufferAndViews({{{EXPORT_NAME}}}.buffer);
+} else {
+  updateGlobalBufferAndViews(wasmMemory.buffer);
 }
+#else
+updateGlobalBufferAndViews(wasmMemory.buffer);
+#endif
+
 #endif
 
 #include "runtime_stack_check.js"
diff --git a/src/settings_internal.js b/src/settings_internal.js
index e77e6ef0b9610..a48bc5a8a0300 100644
--- a/src/settings_internal.js
+++ b/src/settings_internal.js
@@ -187,3 +187,9 @@ var STRUCT_INFO = '';
 var MEMORYPROFILER = 0;
 
 var GENERATE_SOURCE_MAP = 0;
+
+// By default we set this to 0 meaning the wasm file does not defined its own
+// memory and instead the memory is defined in JavaScript.
+// This is set 1 in STANDALONE_WASM or MINIMAL_RUNTIME mode in which case
+// the wasm module exports its memory to JavaScript.
+var MEMORY_DEFINED_IN_WASM = 0;
diff --git a/src/shell_minimal.js b/src/shell_minimal.js
index 2f3597ea712f5..8c1c15c92013e 100644
--- a/src/shell_minimal.js
+++ b/src/shell_minimal.js
@@ -140,12 +140,6 @@ var _scriptDir = (typeof document !== 'undefined' && document.currentScript) ? d
 // coincide.
 var ENVIRONMENT_IS_WORKER = ENVIRONMENT_IS_PTHREAD = typeof importScripts === 'function';
 
-#if MODULARIZE
-if (ENVIRONMENT_IS_WORKER) {
-  var buffer = {{{EXPORT_NAME}}}.buffer;
-}
-#endif
-
 var currentScriptUrl = typeof _scriptDir !== 'undefined' ? _scriptDir : ((typeof document !== 'undefined' && document.currentScript) ? document.currentScript.src : undefined);
 #endif // USE_PTHREADS
 
diff --git a/system/lib/pthread/library_pthread.c b/system/lib/pthread/library_pthread.c
index 447aff8ddbc35..d9ea9e648c43b 100644
--- a/system/lib/pthread/library_pthread.c
+++ b/system/lib/pthread/library_pthread.c
@@ -440,7 +440,7 @@ EMSCRIPTEN_RESULT emscripten_wait_for_call_i(
   return res;
 }
 
-static pthread_t main_browser_thread_id_ = 0;
+static pthread_t main_browser_thread_id_;
 
 void EMSCRIPTEN_KEEPALIVE emscripten_register_main_browser_thread_id(
   pthread_t main_browser_thread_id) {
@@ -448,6 +448,7 @@ void EMSCRIPTEN_KEEPALIVE emscripten_register_main_browser_thread_id(
 }
 
 pthread_t EMSCRIPTEN_KEEPALIVE emscripten_main_browser_thread_id() {
+  assert(main_browser_thread_id_);
   return main_browser_thread_id_;
 }
 
diff --git a/tests/code_size/hello_webgl2_wasm.json b/tests/code_size/hello_webgl2_wasm.json
index 75721e160888f..effc582b06353 100644
--- a/tests/code_size/hello_webgl2_wasm.json
+++ b/tests/code_size/hello_webgl2_wasm.json
@@ -1,10 +1,10 @@
 {
   "a.html": 563,
   "a.html.gz": 377,
-  "a.js": 4957,
-  "a.js.gz": 2373,
-  "a.wasm": 10893,
-  "a.wasm.gz": 6929,
-  "total": 16413,
-  "total_gz": 9679
+  "a.js": 4927,
+  "a.js.gz": 2352,
+  "a.wasm": 10895,
+  "a.wasm.gz": 6927,
+  "total": 16385,
+  "total_gz": 9656
 }
diff --git a/tests/code_size/hello_webgl2_wasm2js.json b/tests/code_size/hello_webgl2_wasm2js.json
index 44382f5c308eb..3e7cef7348cd5 100644
--- a/tests/code_size/hello_webgl2_wasm2js.json
+++ b/tests/code_size/hello_webgl2_wasm2js.json
@@ -1,10 +1,10 @@
 {
   "a.html": 588,
   "a.html.gz": 386,
-  "a.js": 21297,
-  "a.js.gz": 8265,
+  "a.js": 21310,
+  "a.js.gz": 8280,
   "a.mem": 3171,
   "a.mem.gz": 2715,
-  "total": 25056,
-  "total_gz": 11366
+  "total": 25069,
+  "total_gz": 11381
 }
diff --git a/tests/code_size/hello_webgl_wasm.json b/tests/code_size/hello_webgl_wasm.json
index 0a0d2ffb13350..31d1e7bc552b0 100644
--- a/tests/code_size/hello_webgl_wasm.json
+++ b/tests/code_size/hello_webgl_wasm.json
@@ -1,10 +1,10 @@
 {
   "a.html": 563,
   "a.html.gz": 377,
-  "a.js": 4444,
-  "a.js.gz": 2199,
-  "a.wasm": 10893,
-  "a.wasm.gz": 6929,
-  "total": 15900,
-  "total_gz": 9505
+  "a.js": 4410,
+  "a.js.gz": 2172,
+  "a.wasm": 10895,
+  "a.wasm.gz": 6927,
+  "total": 15868,
+  "total_gz": 9476
 }
diff --git a/tests/code_size/hello_webgl_wasm2js.json b/tests/code_size/hello_webgl_wasm2js.json
index af03a30e00692..c2389a3ce2312 100644
--- a/tests/code_size/hello_webgl_wasm2js.json
+++ b/tests/code_size/hello_webgl_wasm2js.json
@@ -1,10 +1,10 @@
 {
   "a.html": 588,
   "a.html.gz": 386,
-  "a.js": 20785,
-  "a.js.gz": 8104,
+  "a.js": 20794,
+  "a.js.gz": 8109,
   "a.mem": 3171,
   "a.mem.gz": 2715,
-  "total": 24544,
-  "total_gz": 11205
+  "total": 24553,
+  "total_gz": 11210
 }
diff --git a/tests/code_size/hello_world_wasm.json b/tests/code_size/hello_world_wasm.json
index 7455f348db944..11563a524b990 100644
--- a/tests/code_size/hello_world_wasm.json
+++ b/tests/code_size/hello_world_wasm.json
@@ -1,10 +1,10 @@
 {
   "a.html": 665,
   "a.html.gz": 427,
-  "a.js": 360,
-  "a.js.gz": 281,
-  "a.wasm": 102,
-  "a.wasm.gz": 114,
-  "total": 1127,
-  "total_gz": 822
+  "a.js": 322,
+  "a.js.gz": 259,
+  "a.wasm": 104,
+  "a.wasm.gz": 112,
+  "total": 1091,
+  "total_gz": 798
 }
diff --git a/tests/code_size/hello_world_wasm2js.json b/tests/code_size/hello_world_wasm2js.json
index dcd139ec5cead..33c37785fbbbc 100644
--- a/tests/code_size/hello_world_wasm2js.json
+++ b/tests/code_size/hello_world_wasm2js.json
@@ -1,10 +1,10 @@
 {
   "a.html": 697,
   "a.html.gz": 437,
-  "a.js": 861,
-  "a.js.gz": 501,
+  "a.js": 1131,
+  "a.js.gz": 605,
   "a.mem": 6,
   "a.mem.gz": 32,
-  "total": 1564,
-  "total_gz": 970
+  "total": 1834,
+  "total_gz": 1074
 }
diff --git a/tests/code_size/random_printf_wasm.json b/tests/code_size/random_printf_wasm.json
index ad5c2bb6c1b7e..32840512adbfa 100644
--- a/tests/code_size/random_printf_wasm.json
+++ b/tests/code_size/random_printf_wasm.json
@@ -1,6 +1,6 @@
 {
-  "a.html": 13665,
-  "a.html.gz": 7313,
-  "total": 13665,
-  "total_gz": 7313
+  "a.html": 13742,
+  "a.html.gz": 7291,
+  "total": 13742,
+  "total_gz": 7291
 }
diff --git a/tests/code_size/random_printf_wasm2js.json b/tests/code_size/random_printf_wasm2js.json
index 596720dae9d00..2a05677eebd5e 100644
--- a/tests/code_size/random_printf_wasm2js.json
+++ b/tests/code_size/random_printf_wasm2js.json
@@ -1,6 +1,6 @@
 {
-  "a.html": 18857,
-  "a.html.gz": 7904,
-  "total": 18857,
-  "total_gz": 7904
+  "a.html": 18972,
+  "a.html.gz": 7942,
+  "total": 18972,
+  "total_gz": 7942
 }
diff --git a/tests/other/metadce/minimal_Os_MINIMAL_RUNTIME.exports b/tests/other/metadce/minimal_Os_MINIMAL_RUNTIME.exports
index de980441c3ab0..d68dd4031d2ad 100644
--- a/tests/other/metadce/minimal_Os_MINIMAL_RUNTIME.exports
+++ b/tests/other/metadce/minimal_Os_MINIMAL_RUNTIME.exports
@@ -1,3 +1,4 @@
 a
 b
 c
+d
diff --git a/tests/other/metadce/minimal_Os_MINIMAL_RUNTIME.sent b/tests/other/metadce/minimal_Os_MINIMAL_RUNTIME.sent
index 2142c3ad3ce3e..8b137891791fe 100644
--- a/tests/other/metadce/minimal_Os_MINIMAL_RUNTIME.sent
+++ b/tests/other/metadce/minimal_Os_MINIMAL_RUNTIME.sent
@@ -1 +1 @@
-memory
+
diff --git a/tests/test_other.py b/tests/test_other.py
index 88a1e4edc1033..d8d4e1567a8da 100644
--- a/tests/test_other.py
+++ b/tests/test_other.py
@@ -6721,7 +6721,7 @@ def strip_numeric_suffixes(funcname):
     'O3': (['-O3'], [], [],          62), # noqa
     'Os': (['-Os'], [], [],          62), # noqa
     'Oz': (['-Oz'], [], [],          62), # noqa
-    'Os_mr': (['-Os', '-s', 'MINIMAL_RUNTIME'], [], [], 62), # noqa
+    'Os_mr': (['-Os', '-s', 'MINIMAL_RUNTIME'], [], [], 74), # noqa
   })
   def test_metadce_minimal(self, *args):
     self.run_metadce_test('minimal.c', *args)
diff --git a/tools/building.py b/tools/building.py
index d8428df17523c..a65b4943056ec 100644
--- a/tools/building.py
+++ b/tools/building.py
@@ -478,10 +478,7 @@ def lld_flags_for_executable(external_symbol_list):
   else:
     cmd.append('--allow-undefined')
 
-  # wasi does not import the memory (but for JS it is efficient to do so,
-  # as it allows us to set up memory, preload files, etc. even before the
-  # wasm module arrives)
-  if not Settings.STANDALONE_WASM:
+  if not Settings.MEMORY_DEFINED_IN_WASM:
     cmd.append('--import-memory')
 
   if Settings.USE_PTHREADS: