isisd: include hash.h, not hash.c
diff --git a/isisd/isis_pdu.c b/isisd/isis_pdu.c
index a2ab064..8219e83 100644
--- a/isisd/isis_pdu.c
+++ b/isisd/isis_pdu.c
@@ -29,7 +29,7 @@
 #include "log.h"
 #include "stream.h"
 #include "vty.h"
-#include "hash.c"
+#include "hash.h"
 #include "prefix.h"
 #include "if.h"
 #include "checksum.h"