diff --git a/sys/netinet/ip_divert.c b/sys/netinet/ip_divert.c
index 6be6d8b4290..b366a65b8b7 100644
--- a/sys/netinet/ip_divert.c
+++ b/sys/netinet/ip_divert.c
@@ -34,7 +34,7 @@ __FBSDID("$FreeBSD$");
 #include "opt_inet6.h"
 #include "opt_sctp.h"
 #ifndef INET
-#error "IPDIVERT requires INET."
+#error "IPDIVERT requires INET"
 #endif
 
 #include <sys/param.h>
diff --git a/sys/netinet/ip_gre.c b/sys/netinet/ip_gre.c
index ae85e9f0ad4..d0274decec4 100644
--- a/sys/netinet/ip_gre.c
+++ b/sys/netinet/ip_gre.c
@@ -70,7 +70,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet/ip_gre.h>
 #include <machine/in_cksum.h>
 #else
-#error ip_gre input without IP?
+#error "ip_gre requires INET"
 #endif
 
 #ifdef NETATALK
diff --git a/sys/netinet/ipfw/ip_fw2.c b/sys/netinet/ipfw/ip_fw2.c
index eec67cc9682..12a7fb9594c 100644
--- a/sys/netinet/ipfw/ip_fw2.c
+++ b/sys/netinet/ipfw/ip_fw2.c
@@ -34,7 +34,7 @@ __FBSDID("$FreeBSD$");
 #include "opt_ipdivert.h"
 #include "opt_inet.h"
 #ifndef INET
-#error IPFIREWALL requires INET.
+#error "IPFIREWALL requires INET"
 #endif /* INET */
 #include "opt_inet6.h"
 #include "opt_ipsec.h"