4 files changed, 17 insertions, 10 deletions

diff --git a/Makefile b/Makefile
index ff259098..5815bb28 100644
--- a/Makefile
+++ b/Makefile
@@ -13,7 +13,7 @@ VERSION	   = 1.9.8
 VDATE	   = 10 October 2009
 
 VFLAGS     = -DVERSION=\"$(VERSION)\"
-CFLAGS    += -W -Wall -Wstrict-prototypes -Wno-unused-parameter -g
+CFLAGS    += -W -Wall -Wstrict-prototypes -Wno-unused-parameter -Wwrite-strings -g
 CFLAGS    += $(VFLAGS)
 LINTFLAGS += $(VFLAGS)
 
diff --git a/html.c b/html.c
index 3ae5e7b2..2c2f65da 100644
--- a/html.c
+++ b/html.c
@@ -21,6 +21,7 @@
 #include <err.h>
 #include <stdio.h>
 #include <stdarg.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -29,11 +30,13 @@
 #include "chars.h"
 #include "html.h"
 
+#define	UNCONST(a)	((void *)(uintptr_t)(const void *)(a))
+
 #define	DOCTYPE		"-//W3C//DTD HTML 4.01//EN"
 #define	DTD		"http://www.w3.org/TR/html4/strict.dtd"
 
 struct	htmldata {
-	char		 *name;
+	const char	 *name;
 	int		  flags;
 #define	HTML_CLRLINE	 (1 << 0)
 #define	HTML_NOSTACK	 (1 << 1)
@@ -87,7 +90,8 @@ void *
 html_alloc(char *outopts)
 {
 	struct html	*h;
-	char		*toks[4], *v;
+	const char	*toks[4];
+	char		*v;
 
 	toks[0] = "style";
 	toks[1] = "man";
@@ -106,7 +110,7 @@ html_alloc(char *outopts)
 	}
 
 	while (outopts && *outopts)
-		switch (getsubopt(&outopts, toks, &v)) {
+		switch (getsubopt(&outopts, UNCONST(toks), &v)) {
 		case (0):
 			h->style = v;
 			break;
@@ -600,7 +604,7 @@ void
 bufcat_su(struct html *h, const char *p, const struct roffsu *su)
 {
 	double		 v;
-	char		*u;
+	const char	*u;
 
 	v = su->scale;
 
diff --git a/html.h b/html.h
index a89e28b1..6846c965 100644
--- a/html.h
+++ b/html.h
@@ -77,7 +77,7 @@ SLIST_HEAD(ordq, ord);
 
 struct	htmlpair {
 	enum htmlattr	  key;
-	char		 *val;
+	const char	 *val;
 };
 
 #define	PAIR_CLASS_INIT(p, v) \
diff --git a/main.c b/main.c
index b9d9da81..aadd86ac 100644
--- a/main.c
+++ b/main.c
@@ -20,6 +20,7 @@
 #include <err.h>
 #include <fcntl.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -27,6 +28,8 @@
 #include "mdoc.h"
 #include "man.h"
 
+#define	UNCONST(a)	((void *)(uintptr_t)(const void *)(a))
+
 /* Account for FreeBSD and Linux in our declarations. */
 
 #ifdef __linux__
@@ -576,7 +579,7 @@ static int
 foptions(int *fflags, char *arg)
 {
 	char		*v, *o;
-	char		*toks[7];
+	const char	*toks[7];
 
 	toks[0] = "ign-scope";
 	toks[1] = "no-ign-escape";
@@ -588,7 +591,7 @@ foptions(int *fflags, char *arg)
 
 	while (*arg) {
 		o = arg;
-		switch (getsubopt(&arg, toks, &v)) {
+		switch (getsubopt(&arg, UNCONST(toks), &v)) {
 		case (0):
 			*fflags |= IGN_SCOPE;
 			break;
@@ -622,7 +625,7 @@ static int
 woptions(int *wflags, char *arg)
 {
 	char		*v, *o;
-	char		*toks[3]; 
+	const char	*toks[3]; 
 
 	toks[0] = "all";
 	toks[1] = "error";
@@ -630,7 +633,7 @@ woptions(int *wflags, char *arg)
 
 	while (*arg) {
 		o = arg;
-		switch (getsubopt(&arg, toks, &v)) {
+		switch (getsubopt(&arg, UNCONST(toks), &v)) {
 		case (0):
 			*wflags |= WARN_WALL;
 			break;