diff --git a/isisd/iso_checksum.h b/isisd/iso_checksum.h
index cf600a8..ba0d198 100644
--- a/isisd/iso_checksum.h
+++ b/isisd/iso_checksum.h
@@ -23,7 +23,7 @@
 #ifndef _ZEBRA_ISO_CSUM_H
 #define _ZEBRA_ISO_CSUM_H
 
-int iso_csum_verify (u_char *buffer, int len, uint16_t *csum);
-u_int16_t iso_csum_create (u_char *buffer, int len, u_int16_t n);
+int iso_csum_verify (u_char * buffer, int len, uint16_t * csum);
+u_int16_t iso_csum_create (u_char * buffer, int len, u_int16_t n);
 
 #endif /* _ZEBRA_ISO_CSUM_H */