diff --git a/src/globals.h b/src/globals.h
index 7ca3ecd..ec6e152 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -1658,6 +1658,9 @@
 
 /* Abort conversion to string after a recursion error. */
 EXTERN int  did_echo_string_emsg INIT(= FALSE);
+
+/* Used for checking if local variables or arguments used in a lambda. */
+EXTERN int *eval_lavars_used INIT(= NULL);
 #endif
 
 /*