diff --git a/test/common.py b/test/common.py
index d26f1f3ee8f29..6569e5e65cfba 100644
--- a/test/common.py
+++ b/test/common.py
@@ -1147,7 +1147,7 @@ def setup_nodefs_test(self):
     if self.get_setting('WASMFS'):
       # without this the JS setup code in setup_nodefs.js doesn't work
       self.set_setting('FORCE_FILESYSTEM')
-    self.emcc_args += ['-DNODEFS', '-lnodefs.js', '--pre-js', test_file('setup_nodefs.js')]
+    self.emcc_args += ['-DNODEFS', '-lnodefs.js', '--pre-js', test_file('setup_nodefs.js'), '-sINCOMING_MODULE_JS_API=[onRuntimeInitialized]']
 
   def setup_noderawfs_test(self):
     self.require_node()
@@ -1336,17 +1336,17 @@ def in_dir(self, *pathelems):
   def add_pre_run(self, code):
     assert not self.get_setting('MINIMAL_RUNTIME')
     create_file('prerun.js', 'Module.preRun = function() { %s }\n' % code)
-    self.emcc_args += ['--pre-js', 'prerun.js']
+    self.emcc_args += ['--pre-js', 'prerun.js', '-sINCOMING_MODULE_JS_API=[preRun]']
 
   def add_post_run(self, code):
     assert not self.get_setting('MINIMAL_RUNTIME')
     create_file('postrun.js', 'Module.postRun = function() { %s }\n' % code)
-    self.emcc_args += ['--pre-js', 'postrun.js']
+    self.emcc_args += ['--pre-js', 'postrun.js', '-sINCOMING_MODULE_JS_API=[postRun]']
 
   def add_on_exit(self, code):
     assert not self.get_setting('MINIMAL_RUNTIME')
     create_file('onexit.js', 'Module.onExit = function() { %s }\n' % code)
-    self.emcc_args += ['--pre-js', 'onexit.js']
+    self.emcc_args += ['--pre-js', 'onexit.js', '-sINCOMING_MODULE_JS_API=[onExit]']
 
   # returns the full list of arguments to pass to emcc
   # param @main_file whether this is the main file of the test. some arguments
diff --git a/test/core/test_core_types.c b/test/core/test_core_types.c
index 881df580ae2e2..1dd736e5b4d51 100644
--- a/test/core/test_core_types.c
+++ b/test/core/test_core_types.c
@@ -77,7 +77,10 @@
 
 // We prefer to use __EMSCRIPTEN__, but for compatibility, we define
 // EMSCRIPTEN too.
-#ifndef EMSCRIPTEN
+#if defined(IN_STRICT_MODE) && defined(EMSCRIPTEN)
+#error When compiling in -sSTRICT mode, EMSCRIPTEN should not be defined, but it was!
+#endif
+#if !defined(IN_STRICT_MODE) && !defined(EMSCRIPTEN)
 #error EMSCRIPTEN is not defined
 #endif
 
diff --git a/test/core/test_getValue_setValue.cpp b/test/core/test_getValue_setValue.cpp
index c2d68b520d816..e2e3aaec87c10 100644
--- a/test/core/test_getValue_setValue.cpp
+++ b/test/core/test_getValue_setValue.cpp
@@ -15,20 +15,20 @@ int main() {
     setValue($0, 1234, 'i32');
     out('i32: ' + getValue($0, 'i32'));
 #ifdef WASM_BIGINT
-    i64 = getValue($1, 'i64');
+    var i64 = getValue($1, 'i64');
     out('i64: 0x' + i64.toString(16) + ' ' + typeof(i64));
 #endif
-    ptr = getValue($1, '*');
+    var ptr = getValue($1, '*');
     out('ptr: 0x' + ptr.toString(16) + ' ' + typeof(ptr));
 #else
     out('i32: ' + getValue($0, 'i32'));
     Module['setValue']($0, 1234, 'i32');
     out('i32: ' + Module['getValue']($0, 'i32'));
 #ifdef WASM_BIGINT
-    i64 = Module['getValue']($1, 'i64');
+    var i64 = Module['getValue']($1, 'i64');
     out('i64: 0x' + i64.toString(16) + ' ' + typeof(i64));
 #endif
-    ptr = Module['getValue']($1, '*');
+    var ptr = Module['getValue']($1, '*');
     out('ptr: 0x' + ptr.toString(16) + ' ' + typeof(ptr));
 #endif
 
diff --git a/test/test_core.py b/test/test_core.py
index 15f0b694f3527..38c4c0ff14f4b 100644
--- a/test/test_core.py
+++ b/test/test_core.py
@@ -383,6 +383,7 @@ def decorated(self, textdecoder, *args, **kwargs):
 
 no_minimal_runtime = make_no_decorator_for_setting('MINIMAL_RUNTIME')
 no_safe_heap = make_no_decorator_for_setting('SAFE_HEAP')
+no_strict = make_no_decorator_for_setting('STRICT')
 
 
 def is_sanitizing(args):
@@ -646,6 +647,8 @@ def test_sha1(self):
     self.do_runf('third_party/sha1.c', 'SHA1=15dd99a1991e0b3826fede3deffc1feba42278e6')
 
   def test_core_types(self):
+    if self.get_setting('STRICT'):
+      self.emcc_args += ['-DIN_STRICT_MODE=1']
     self.do_runf('core/test_core_types.c')
 
   def test_cube2md5(self):
@@ -2649,6 +2652,7 @@ def test_pthread_abort(self):
     # handler will only be present in the main thread (much like it would if it
     # was passed in by pre-populating the module object on prior to loading).
     self.add_pre_run("Module.onAbort = () => console.log('onAbort called');")
+    self.emcc_args += ['-sINCOMING_MODULE_JS_API=[preRun,onAbort]']
     self.do_run_in_out_file_test('pthread/test_pthread_abort.c', assert_returncode=NON_ZERO)
 
   @node_pthreads
@@ -4159,7 +4163,7 @@ def test_dylink_locate_file(self):
       }
     };
     ''' % (so_name, so_dir))
-    self.do_basic_dylink_test(so_dir=so_dir, so_name=so_name, main_emcc_args=['--pre-js', 'pre.js'])
+    self.do_basic_dylink_test(so_dir=so_dir, so_name=so_name, main_emcc_args=['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[locateFile]'])
 
   @with_dylink_reversed
   def test_dylink_function_pointer_equality(self):
@@ -5209,7 +5213,7 @@ class Bar : public Foo {
   @needs_dylink
   def test_dylink_argv_argc(self):
     # Verify that argc and argv can be sent to main when main is in a side module
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '--no-entry', '-sINCOMING_MODULE_JS_API=[arguments]']
     create_file('pre.js', "Module['arguments'] = ['hello', 'world!']")
     self.dylink_test(
       '', # main module is empty.
@@ -5424,6 +5428,7 @@ def test_langinfo(self):
     self.do_core_test('test_langinfo.c')
 
   @no_modularize_instance('uses Module object directly')
+  @no_strict('TODO: Fails in -sSTRICT mode due to an unknown reason.')
   def test_files(self):
     # Use closure here, to test we don't break FS stuff
     if '-O3' in self.emcc_args and self.is_wasm2js():
@@ -5435,7 +5440,7 @@ def test_files(self):
     else:
       self.maybe_closure()
 
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[preRun]']
     self.set_setting('FORCE_FILESYSTEM')
 
     create_file('pre.js', '''
@@ -5467,7 +5472,7 @@ def test_module_stdin(self):
       stdout: (x) => out('got: ' + x)
     };
     ''')
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[stdin,stdout]']
 
     src = r'''
       #include <stdio.h>
@@ -5916,7 +5921,7 @@ def test_fs_no_main(self):
 ''')
     self.set_setting('EXPORTED_FUNCTIONS', '_foo')
     self.set_setting('FORCE_FILESYSTEM')
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[preRun, onRuntimeInitialized]']
     self.do_run('int foo() { return 42; }', '', force_c=True)
 
   @also_with_noderawfs
@@ -6159,6 +6164,8 @@ def test_posixtime(self):
     self.do_core_test('test_posixtime.c')
 
   def test_uname(self):
+    if self.get_setting('STRICT'):
+      self.emcc_args += ['-lstubs']
     self.do_core_test('test_uname.c', regex=True)
 
   def test_unary_literal(self):
@@ -6188,6 +6195,8 @@ def test_stddef(self):
     self.do_core_test('test_stddef.cpp', force_c=True)
 
   def test_getloadavg(self):
+    if self.get_setting('STRICT'):
+      self.emcc_args += ['-lstubs']
     self.do_core_test('test_getloadavg.c')
 
   def test_nl_types(self):
@@ -6717,6 +6726,10 @@ def test_gcc_unmangler(self):
   @needs_make('configure script')
   @is_slow_test
   def test_freetype(self):
+    # Not needed for js, but useful for debugging
+    shutil.copy(test_file('freetype/LiberationSansBold.ttf'), 'font.ttf')
+    ftlib = self.get_freetype_library()
+
     if self.get_setting('WASMFS'):
       self.emcc_args += ['-sFORCE_FILESYSTEM']
 
@@ -6724,10 +6737,6 @@ def test_freetype(self):
       list(bytearray(read_binary(test_file('freetype/LiberationSansBold.ttf')))),
     ))
 
-    # Not needed for js, but useful for debugging
-    shutil.copy(test_file('freetype/LiberationSansBold.ttf'), 'font.ttf')
-    ftlib = self.get_freetype_library()
-
     # Main
     self.do_run_in_out_file_test('freetype/main.c',
                                  args=['font.ttf', 'test!', '150', '120', '25'],
@@ -6763,6 +6772,8 @@ def test_freetype(self):
     'pthreads': (True,),
   })
   def test_sqlite(self, use_pthreads):
+    if self.get_setting('STRICT'):
+      self.emcc_args += ['-lstubs']
     if use_pthreads:
       self.emcc_args.append('-pthread')
       self.setup_node_pthreads()
@@ -6847,7 +6858,7 @@ def test_poppler(self):
       out("Data: " + JSON.stringify(FileData.map(function(x) { return unSign(x, 8) })));
     };
     ''')
-    self.emcc_args += ['--pre-js', 'pre.js', '-sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE=$unSign']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE=$unSign', '-sINCOMING_MODULE_JS_API=[preRun, postRun]']
 
     ppm_data = str(list(bytearray(read_binary(test_file('poppler/ref.ppm')))))
     self.do_run('', ppm_data.replace(' ', ''),
@@ -6935,7 +6946,7 @@ def image_compare(output):
       assert diff_mean < 0.01, diff_mean
 
     self.emcc_args += ['--minify=0'] # to compare the versions
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[preRun,postRun]']
 
     output = self.do_runf('third_party/openjpeg/codec/j2k_to_image.c',
                           'Successfully generated', # The real test for valid output is in image_compare
@@ -7135,6 +7146,7 @@ def test(output_prefix='', args=None, assert_returncode=0):
     test(args=['-sFORCE_FILESYSTEM'])
 
   @no_modularize_instance('uses Module object directly')
+  @no_strict('This test verifies legacy behavior that does not apply to -sSTRICT builds.')
   def test_legacy_exported_runtime_numbers(self):
     # these used to be exported, but no longer are by default
     def test(expected, args=None, assert_returncode=0):
@@ -7573,7 +7585,7 @@ def test_embind_val_coro(self):
     create_file('pre.js', r'''Module.onRuntimeInitialized = () => {
       Module.asyncCoro().then(console.log);
     }''')
-    self.emcc_args += ['-std=c++20', '--bind', '--pre-js=pre.js']
+    self.emcc_args += ['-std=c++20', '--bind', '--pre-js=pre.js', '-sINCOMING_MODULE_JS_API=[onRuntimeInitialized]', '--no-entry']
     self.do_runf('embind/test_val_coro.cpp', '34\n')
 
   def test_embind_val_coro_caught(self):
@@ -7584,7 +7596,7 @@ def test_embind_val_coro_caught(self):
         err => console.error(`rejected with: ${err.stack}`)
       );
     }''')
-    self.emcc_args += ['-std=c++20', '--bind', '--pre-js=pre.js', '-fexceptions']
+    self.emcc_args += ['-std=c++20', '--bind', '--pre-js=pre.js', '-fexceptions', '-sINCOMING_MODULE_JS_API=[onRuntimeInitialized]', '--no-entry']
     self.do_runf('embind/test_val_coro.cpp', 'rejected with: std::runtime_error: bang from throwingCoro!\n')
 
   def test_embind_dynamic_initialization(self):
@@ -7688,6 +7700,7 @@ def test_embind_wasm_workers(self):
     'all_growth': ('ALL', True),
   })
   @no_modularize_instance('uses Module global')
+  @no_strict('TODO: Fails in -sSTRICT mode due to an unknown reason.')
   def test_webidl(self, mode, allow_memory_growth):
     self.set_setting('WASM_ASYNC_COMPILATION', 0)
     if self.maybe_closure():
@@ -8055,7 +8068,7 @@ def test_exit_status(self):
         assert(status == EXITSTATUS);
       };
     ''')
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[onExit]']
     print('.. exit')
     self.do_runf('exit.c', 'hello, world!\ncleanup\nI see exit status: 117', assert_returncode=117, emcc_args=['-DNORMAL_EXIT'])
     print('.. _exit')
@@ -8172,7 +8185,7 @@ def test_async_ccall_bad(self):
   }
 };
 ''')
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[onRuntimeInitialized]']
     self.do_runf('main.c', 'The call to main is running asynchronously.')
 
   @with_asyncify_and_jspi
@@ -8197,7 +8210,7 @@ def test_async_ccall_good(self):
   ccall('main', null, ['number', 'string'], [2, 'waka'], { async: true });
 };
 ''')
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[onRuntimeInitialized]']
     self.do_runf('main.c', 'HelloWorld')
 
   @parameterized({
@@ -8242,7 +8255,7 @@ def test_async_ccall_promise(self, exit_runtime):
     });
 };
 ''')
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[onRuntimeInitialized]']
     self.do_runf('main.c', 'stringf: first\nsecond\n6.4')
 
   @no_esm_integration('WASM_ESM_INTEGRATION is not compatible with ASYNCIFY=1')
@@ -8582,7 +8595,7 @@ def test_fs_dict(self):
         out(typeof NODEFS);
       };
     ''')
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[preRun]']
     self.do_run('int main() { return 0; }', 'object\nobject\nobject\nobject\nobject\nobject')
 
   def test_fs_dict_none(self):
@@ -8606,7 +8619,7 @@ def test_fs_dict_none(self):
         }
       };
     ''')
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[preRun]']
     expected = '''\
 object
 undefined
@@ -8715,7 +8728,7 @@ def test_postrun_exception(self):
   def test_postrun_exit_runtime(self):
     create_file('pre.js', "Module['postRun'] = () => err('post run\\n');")
     self.set_setting('EXIT_RUNTIME')
-    self.emcc_args.append('--pre-js=pre.js')
+    self.emcc_args += ['--pre-js=pre.js', '-sINCOMING_MODULE_JS_API=[postRun]']
     self.do_runf('hello_world.c', 'post run')
 
   # Tests that building with -sDECLARE_ASM_MODULE_EXPORTS=0 works
@@ -9233,7 +9246,7 @@ def test_pthread_exceptions(self):
   def test_pthread_exit_process(self):
     self.set_setting('PROXY_TO_PTHREAD')
     self.set_setting('EXIT_RUNTIME')
-    self.emcc_args += ['-DEXIT_RUNTIME', '--pre-js', test_file('core/pthread/test_pthread_exit_runtime.pre.js')]
+    self.emcc_args += ['-DEXIT_RUNTIME', '--pre-js', test_file('core/pthread/test_pthread_exit_runtime.pre.js'), '-sINCOMING_MODULE_JS_API=[onRuntimeInitialized, onExit]']
     self.do_run_in_out_file_test('core/pthread/test_pthread_exit_runtime.c', assert_returncode=42)
 
   @node_pthreads
@@ -9401,6 +9414,10 @@ def test_pthread_dylink_longjmp(self):
   @needs_dylink
   @node_pthreads
   def test_pthread_dylink_main_module_1(self):
+    # TODO: For some reason, -lhtml5 must be passed in -sSTRICT mode, but can NOT
+    # be passed when not compiling in -sSTRICT mode. That does not seem intentional?
+    if self.get_setting('STRICT'):
+      self.emcc_args += ['-lhtml5']
     self.emcc_args += ['-Wno-experimental', '-pthread']
     self.set_setting('MAIN_MODULE')
     self.do_runf('hello_world.c')
@@ -9413,7 +9430,7 @@ def test_pthread_dylink_main_module_1(self):
   def test_Module_dynamicLibraries(self, args):
     # test that Module.dynamicLibraries works with pthreads
     self.emcc_args += args
-    self.emcc_args += ['--pre-js', 'pre.js']
+    self.emcc_args += ['--pre-js', 'pre.js', '-sINCOMING_MODULE_JS_API=[dynamicLibraries]']
     self.emcc_args += ['--js-library', 'lib.js']
     # This test is for setting dynamicLibraries at runtime, so we don't
     # want emscripten loading `liblib.so` automatically (which it would
@@ -9534,7 +9551,7 @@ def test_abort_on_exceptions(self):
     self.set_setting('ABORT_ON_WASM_EXCEPTIONS')
     self.set_setting('ALLOW_TABLE_GROWTH')
     self.set_setting('EXPORTED_RUNTIME_METHODS', ['ccall', 'cwrap'])
-    self.set_setting('DEFAULT_LIBRARY_FUNCS_TO_INCLUDE', ['$addFunction'])
+    self.set_setting('DEFAULT_LIBRARY_FUNCS_TO_INCLUDE', ['$addFunction', '$addOnPostRun'])
     self.emcc_args += ['-lembind', '--post-js', test_file('core/test_abort_on_exceptions_post.js')]
     self.do_core_test('test_abort_on_exceptions.cpp', interleaved_output=False)
 
@@ -9561,6 +9578,10 @@ def test_abort_on_exceptions_pthreads(self):
 
   @needs_dylink
   def test_gl_main_module(self):
+    # TODO: For some reason, -lGL must be passed in -sSTRICT mode, but can NOT
+    # be passed when not compiling in -sSTRICT mode. That does not seem intentional?
+    if self.get_setting('STRICT'):
+      self.emcc_args += ['-lGL']
     self.set_setting('MAIN_MODULE')
     self.emcc_args += ['-sGL_ENABLE_GET_PROC_ADDRESS']
     self.do_runf('core/test_gl_get_proc_address.c')
@@ -9589,6 +9610,8 @@ def test_embind_lib_with_asyncify(self, args):
       '-sASYNCIFY_IMPORTS=sleep_and_return',
       '-sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE=$ASSERTIONS',
       '--post-js', test_file('core/embind_lib_with_asyncify.test.js'),
+      '--no-entry',
+      '-sINCOMING_MODULE_JS_API=[onRuntimeInitialized]',
     ]
     self.emcc_args += args
     self.do_core_test('embind_lib_with_asyncify.cpp')