diff --git a/build_tools/cflags.xml b/build_tools/cflags.xml
index 994c96203e..3eebd5d0a0 100644
--- a/build_tools/cflags.xml
+++ b/build_tools/cflags.xml
@@ -11,6 +11,8 @@
 		</member>
 		<member name="DO_CRASH" displayname="Crash on fatal errors">
 		</member>
+		<member name="THREAD_CRASH" displayname="Crash on mutex errors">
+		</member>
 		<member name="DONT_OPTIMIZE" displayname="Disable Optimizations by the Compiler">
 		</member>
 		<member name="DUMP_SCHEDULER" displayname="Dump Scheduler Contents for Debugging">