diff --git a/modules/bullet/SCsub b/modules/bullet/SCsub
index b853ebfc637..21bdcca18e9 100644
--- a/modules/bullet/SCsub
+++ b/modules/bullet/SCsub
@@ -201,8 +201,8 @@ if env["builtin_bullet"]:
         env_bullet.Append(CPPFLAGS=["-isystem", Dir(thirdparty_dir).path])
     else:
         env_bullet.Prepend(CPPPATH=[thirdparty_dir])
-    # if env['target'] == "debug" or env['target'] == "release_debug":
-    #     env_bullet.Append(CPPDEFINES=['BT_DEBUG'])
+    if env["target"] == "debug" or env["target"] == "release_debug":
+        env_bullet.Append(CPPDEFINES=["DEBUG"])
 
     env_bullet.Append(CPPDEFINES=["BT_USE_OLD_DAMPING_METHOD"])