diff --git a/src/ex_cmds.h b/src/ex_cmds.h
index ef3fa66..8596b24 100644
--- a/src/ex_cmds.h
+++ b/src/ex_cmds.h
@@ -1853,7 +1853,7 @@
 	EX_RANGE|EX_WHOLEFOLD|EX_EXTRA|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK|EX_NONWHITE_OK,
 	ADDR_LINES),
 EXCMD(CMD_block,	"{",		ex_block,  // not found normally
-	EX_TRLBAR,
+	EX_TRLBAR|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_endblock,	"}",		ex_endblock,
 	EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,