diff --git a/tools/ports/cocos2d.py b/tools/ports/cocos2d.py
index 47814fc62b6a6..eef83bec5fbcd 100644
--- a/tools/ports/cocos2d.py
+++ b/tools/ports/cocos2d.py
@@ -23,7 +23,6 @@ def get(ports, settings, shared):
     'cocos2d', 'https://github.com/emscripten-ports/Cocos2d/archive/' + TAG + '.zip', 'Cocos2d-' + TAG, sha512hash=HASH)
 
   def create(final):
-    logging.info('building port: cocos2d v3')
     logging.warn('cocos2d: library is experimental, do not expect that it will work out of the box')
 
     cocos2d_src = os.path.join(ports.get_dir(), 'cocos2d')
@@ -51,6 +50,9 @@ def create(final):
                  '-DCC_KEYBOARD_SUPPORT',
                  '-DGL_ES=1',
                  '-DNDEBUG', # '-DCOCOS2D_DEBUG=1' 1 - error/warn, 2 - verbose
+                 # Cocos2d source code hasn't switched to __EMSCRIPTEN__.
+                 # See https://github.com/emscripten-ports/Cocos2d/pull/3
+                 '-DEMSCRIPTEN',
                  '-DCP_USE_DOUBLES=0',
                  '-O2',
                  '-sUSE_ZLIB=1',
diff --git a/tools/system_libs.py b/tools/system_libs.py
index cee7d93be74f7..43e9f322c942d 100644
--- a/tools/system_libs.py
+++ b/tools/system_libs.py
@@ -43,7 +43,7 @@ def glob_in_path(path, glob_pattern, excludes=()):
 def get_base_cflags(force_object_files=False):
   # Always build system libraries with debug information.  Non-debug builds
   # will ignore this at link time because we link with `-strip-debug`.
-  flags = ['-g']
+  flags = ['-g', '-sSTRICT']
   if settings.LTO and not force_object_files:
     flags += ['-flto=' + settings.LTO]
   if settings.RELOCATABLE: