diff --git a/demos/meson.build b/demos/meson.build
index 7cc6383..8fb051b 100644
--- a/demos/meson.build
+++ b/demos/meson.build
@@ -9,7 +9,7 @@ external_inc = include_directories('external/sources/')
 
 # Argumesnts
 not_wasm = host_machine.cpu_family() != 'wasm32'
-versions = ['BindSDL_Image','SDL_209', 'BindBC_Static', 'BindSDL_Static', 'MM_USE_POSIX_THREADS', 'ECSEmscripten']
+versions = ['BindSDL_Image','SDL_208', 'BindBC_Static', 'BindSDL_Static']
 
 # Dependencies
 bindbc_loader_dep = dependency('bindbc-loader')
@@ -40,6 +40,8 @@ if not_wasm
 
 	test('basic-tests', exe)
 else
+	versions += ['MM_USE_POSIX_THREADS', 'ECSEmscripten']
+
 	decs_demos_lib = library('decs-demos', [demos_src, external_src],
 		include_directories : [demos_inc, external_inc],
 		d_module_versions : versions,
@@ -57,6 +59,7 @@ else
 		build_by_default: true,
 	)
 
+	# build single-threaded demos with HTML output
 	wasm_web = custom_target('decs-demos-wasm-web',
 		command: [emcc, args_wasm, '--pre-js', packed_assets, '-o', '@OUTPUT@', '@INPUT@'],
 		input: [sdl2_lib, ecs_lib, decs_demos_lib, ecs_utils_lib, cimgui_lib],
@@ -64,12 +67,14 @@ else
 		build_by_default: true,
 	)
 	
+	# build multi-threded demos with JS output. Custom shellfile detects if web browser threads are enabled and select proper JS and WASM.
 	wasm_web_mt = custom_target('decs-demos-wasm-web-mt',
 		command: [emcc, args_wasm, '-s', 'USE_PTHREADS=1', '--pre-js', packed_assets, '-o', '@OUTPUT@', '@INPUT@'],
 		input: [sdl2_lib, ecs_lib, decs_demos_lib, ecs_utils_lib, cimgui_lib],
 		output: ['ecs_demo_mt.js'],
 		build_by_default: true,
 	)
+
 	summary('decs-demoswasm-index', wasm_web.full_path())
 endif
 
diff --git a/meson.build b/meson.build
index 9d83e58..f4de9a3 100644
--- a/meson.build
+++ b/meson.build
@@ -52,10 +52,13 @@ endif
 add_global_arguments(args, language : 'd')
 add_global_link_arguments(link_args, language : 'd')
 
+versions = []
+
 if host_machine.cpu_family() == 'wasm32'
 	add_global_arguments('--output-bc', language : 'd') # Adding it in cross files breaks linker detection
 	emcc = find_program('emcc')
 	args_wasm = ['-O3', '-s', 'FORCE_FILESYSTEM=1', '-s', 'USE_SDL=2', '-s', 'USE_SDL_IMAGE=2', '-s', 'SDL2_IMAGE_FORMATS=["png"]', '-s', 'ERROR_ON_UNDEFINED_SYMBOLS=0', '-s', 'ALLOW_MEMORY_GROWTH=1', '-s', 'WASM_MEM_MAX=1024MB', '-s', 'MALLOC=dlmalloc', '-s', 'WASM=1', '--shell-file', '../demos/emscripten_multi_shell.html', '-s', 'DISABLE_DEPRECATED_FIND_EVENT_TARGET_BEHAVIOR=1']
+	versions = ['ECSEmscripten']
 endif
 
 
@@ -64,6 +67,7 @@ threads_dep = dependency('threads')
 
 ecs_lib = library('decs', src,
 	include_directories : [inc],
+	d_module_versions : versions
 )
 
 decs_dep = declare_dependency(
diff --git a/tests/meson.build b/tests/meson.build
index 45c0ea1..dbf051d 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -20,6 +20,7 @@ if host_machine.cpu_family() != 'wasm32'
 else
 	tests_lib = library('decs-tests', tests_src,
 		include_directories : [inc],
+		d_module_versions : ['ECSEmscripten'],
 	)
 	wasm_web = custom_target('wasm-web',
 		command: [emcc, args_wasm, '-o', '@OUTPUT@', '@INPUT@'],