diff --git a/bin/chflags/chflags.c b/bin/chflags/chflags.c
index 02137eb30c34..2c07db9becc4 100644
--- a/bin/chflags/chflags.c
+++ b/bin/chflags/chflags.c
@@ -53,7 +53,7 @@ __FBSDID("$FreeBSD$");
 #include <string.h>
 #include <unistd.h>
 
-void	usage(void);
+static void usage(void);
 
 int
 main(int argc, char *argv[])
@@ -196,7 +196,7 @@ main(int argc, char *argv[])
 	exit(rval);
 }
 
-void
+static void
 usage(void)
 {
 	(void)fprintf(stderr,
diff --git a/bin/chmod/chmod.c b/bin/chmod/chmod.c
index e96738898031..6736032466cc 100644
--- a/bin/chmod/chmod.c
+++ b/bin/chmod/chmod.c
@@ -53,7 +53,7 @@ __FBSDID("$FreeBSD$");
 #include <string.h>
 #include <unistd.h>
 
-void usage(void);
+static void usage(void);
 
 int
 main(int argc, char *argv[])
@@ -212,7 +212,7 @@ done:	argv += optind;
 	exit(rval);
 }
 
-void
+static void
 usage(void)
 {
 	(void)fprintf(stderr,
diff --git a/bin/df/df.c b/bin/df/df.c
index 49c2d9f1e1c6..be811a149428 100644
--- a/bin/df/df.c
+++ b/bin/df/df.c
@@ -476,7 +476,7 @@ prtstat(struct statfs *sfsp, struct maxwidths *mwp)
 	(void)printf("\n");
 }
 
-void
+static void
 addstat(struct statfs *totalfsp, struct statfs *statfsp)
 {
 	uint64_t bsize;
diff --git a/bin/hostname/hostname.c b/bin/hostname/hostname.c
index 7aaca9ccda70..87136eb5f408 100644
--- a/bin/hostname/hostname.c
+++ b/bin/hostname/hostname.c
@@ -49,7 +49,7 @@ __FBSDID("$FreeBSD$");
 #include <string.h>
 #include <unistd.h>
 
-void usage(void);
+static void usage(void);
 
 int
 main(int argc, char *argv[])
@@ -96,7 +96,7 @@ main(int argc, char *argv[])
 	exit(0);
 }
 
-void
+static void
 usage(void)
 {