diff --git a/usr.bin/top/Makefile b/usr.bin/top/Makefile
index d778e07c8c14..148fd96c1914 100644
--- a/usr.bin/top/Makefile
+++ b/usr.bin/top/Makefile
@@ -7,14 +7,9 @@ SRCS=	commands.c display.c machine.c screen.c top.c \
 	username.c utils.c
 MAN=	top.1
 
-.if ${COMPILER_TYPE} == "gcc"
-.if ${COMPILER_VERSION} >= 50000
-CFLAGS.gcc=-Wno-error=discarded-qualifiers -Wno-error=incompatible-pointer-types
-.else #base gcc
+.if ${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} < 50000
 NO_WERROR=
 .endif
-.endif
-CFLAGS.clang=-Wno-error=incompatible-pointer-types-discards-qualifiers
 
 LIBADD=	ncursesw m kvm jail util sbuf
 .include <bsd.prog.mk>
diff --git a/usr.bin/top/display.c b/usr.bin/top/display.c
index 862d2a944c89..03277ea86cf2 100644
--- a/usr.bin/top/display.c
+++ b/usr.bin/top/display.c
@@ -184,7 +184,7 @@ int
 display_init(struct statics * statics)
 {
     int lines;
-    char **pp;
+    const char * const *pp;
     int *ip;
     int i;
 
@@ -516,8 +516,8 @@ void
 z_cpustates(void)
 {
     int i = 0;
-    const char **names;
-    char *thisname;
+    const char * const *names;
+    const char *thisname;
     int cpu, value;
 
     for (cpu = 0; cpu < num_cpus; cpu++) {
@@ -751,7 +751,7 @@ static int header_length;
  * allocated area with the trimmed header.
  */
 
-const char *
+char *
 trim_header(const char *text)
 {
 	char *s;
diff --git a/usr.bin/top/display.h b/usr.bin/top/display.h
index 5b5aa32fe220..546f21ce34b0 100644
--- a/usr.bin/top/display.h
+++ b/usr.bin/top/display.h
@@ -27,7 +27,7 @@ void	 i_timeofday(time_t *tod);
 void	 i_uptime(struct timeval *bt, time_t *tod);
 void	 new_message(int type, const char *msgfmt, ...);
 int	 readline(char *buffer, int size, int numeric);
-const char	*trim_header(const char *text);
+char	*trim_header(const char *text);
 void	 u_arc(int *stats);
 void	 u_carc(int *stats);
 void	 u_cpustates(int *states);
diff --git a/usr.bin/top/machine.c b/usr.bin/top/machine.c
index 374c9da0edf4..563efc624e24 100644
--- a/usr.bin/top/machine.c
+++ b/usr.bin/top/machine.c
@@ -618,7 +618,7 @@ get_old_proc(struct kinfo_proc *pp)
 		pp->ki_udata = NOPROC;
 		return (NULL);
 	}
-	pp->ki_udata = oldp;
+	pp->ki_udata = __DECONST(void *, oldp);
 	return (oldp);
 }
 
@@ -634,7 +634,7 @@ get_io_stats(const struct kinfo_proc *pp, long *inp, long *oup, long *flp,
 	static struct kinfo_proc dummy;
 	long ret;
 
-	oldp = get_old_proc(pp);
+	oldp = get_old_proc(__DECONST(struct kinfo_proc *, pp));
 	if (oldp == NULL) {
 		memset(&dummy, 0, sizeof(dummy));
 		oldp = &dummy;
diff --git a/usr.bin/top/top.c b/usr.bin/top/top.c
index 80fa446fc7b1..650789689b6b 100644
--- a/usr.bin/top/top.c
+++ b/usr.bin/top/top.c
@@ -219,7 +219,7 @@ handle_user(char *buf, size_t buflen)
 }
 
 int
-main(int argc, char *argv[])
+main(int argc, const char *argv[])
 {
     int i;
     int active_procs;
@@ -306,7 +306,7 @@ main(int argc, char *argv[])
 	    optind = 1;
 	}
 
-	while ((i = getopt_long(ac, av, "CSIHPabijJ:nquvzs:d:U:m:o:p:Ttw", longopts, NULL)) != EOF)
+	while ((i = getopt_long(ac, __DECONST(char * const *, av), "CSIHPabijJ:nquvzs:d:U:m:o:p:Ttw", longopts, NULL)) != EOF)
 	{
 	    switch(i)
 	    {
diff --git a/usr.bin/top/utils.c b/usr.bin/top/utils.c
index 93bbcad09dc4..1ac0d6ad1516 100644
--- a/usr.bin/top/utils.c
+++ b/usr.bin/top/utils.c
@@ -146,7 +146,7 @@ string_index(const char *string, const char * const *array)
  *	squat about quotes.
  */
 
-const char * const *
+const char **
 argparse(char *line, int *cntp)
 {
     const char **ap;
diff --git a/usr.bin/top/utils.h b/usr.bin/top/utils.h
index 106e1da08963..2688f5518575 100644
--- a/usr.bin/top/utils.h
+++ b/usr.bin/top/utils.h
@@ -16,7 +16,7 @@ int atoiwi(const char *);
 char *itoa(unsigned int);
 char *itoa7(int);
 int digits(int);
-const char * const *argparse(char *, int *);
+const char **argparse(char *, int *);
 long percentages(int, int *, long *, long *, long *);
 const char *format_time(long);
 char *format_k(int64_t);