1 files changed, 4 insertions, 0 deletions
diff --git a/kwset.h b/kwset.h
index df99a92178..f50ecae573 100644
--- a/kwset.h
+++ b/kwset.h
@@ -1,3 +1,6 @@
+#ifndef KWSET_H
+#define KWSET_H
+
 /* This file has been copied from commit e7ac713d^ in the GNU grep git
  * repository. A few small changes have been made to adapt the code to
  * Git.
@@ -59,3 +62,4 @@ size_t kwsexec(kwset_t, char const *, size_t, struct kwsmatch *);
 /* Deallocate the given keyword set and all its associated storage. */
 void kwsfree(kwset_t);
 
+#endif /* KWSET_H */