diff --git a/shell/match.h b/shell/match.h
index 90597ee..98ff874 100644
--- a/shell/match.h
+++ b/shell/match.h
@@ -1,5 +1,8 @@
 /* match.h - interface to shell ##/%% matching code */
 
+#ifndef SHELL_MATCH_H
+#define SHELL_MATCH_H 1
+
 PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 
 typedef char *(*scan_t)(char *string, char *match, bool match_at_left);
@@ -24,3 +27,5 @@
 }
 
 POP_SAVED_FUNCTION_VISIBILITY
+
+#endif