diff --git a/src/util/irep_ids.def b/src/util/irep_ids.def
index 4bc64e911e3..78ff9b00e16 100644
--- a/src/util/irep_ids.def
+++ b/src/util/irep_ids.def
@@ -666,5 +666,13 @@ IREP_ID_TWO(overlay_class, java::com.diffblue.OverlayClassImplementation)
 IREP_ID_TWO(overlay_method, java::com.diffblue.OverlayMethodImplementation)
 IREP_ID_ONE(annotations)
 
+// Projects depending on this code base that wish to extend the list of
+// available ids should provide a file local_irep_ids.h in their source tree and
+// add -D'LOCAL_IREP_IDS=<project/local_irep_ids.h>' to their compiler command
+// line.
+#ifdef LOCAL_IREP_IDS
+#include LOCAL_IREP_IDS
+#endif
+
 #undef IREP_ID_ONE
 #undef IREP_ID_TWO