diff --git a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -12,9 +12,9 @@ LINKS=	${BINDIR}/rcs ${BINDIR}/ci ${BIND
 	${BINDIR}/rcs ${BINDIR}/rcsclean ${BINDIR}/rcs ${BINDIR}/rcsdiff \
 	${BINDIR}/rcs ${BINDIR}/rcsmerge ${BINDIR}/rcs ${BINDIR}/rlog
 
 CPPFLAGS+=-I${.CURDIR}
-CFLAGS+=-Wall
+CFLAGS+=-Wall -I${.CURDIR}
 CFLAGS+=-Wstrict-prototypes -Wmissing-prototypes
 CFLAGS+=-Wmissing-declarations
 CFLAGS+=-Wshadow -Wpointer-arith -Wcast-qual
 CFLAGS+=-Wsign-compare
diff --git a/ci.c b/ci.c
--- a/ci.c
+++ b/ci.c
@@ -909,9 +909,9 @@ checkin_keywordscan(BUF *data, RCSNUM **
 		buf_append(buf, start, len);
 
 		/* XXX - Not binary safe. */
 		buf_putc(buf, '\0');
-		checkin_parsekeyword(buf_get(buf), rev, date, author, state);
+		checkin_parsekeyword((char *)buf_get(buf), rev, date, author, state);
 		buf_free(buf);
 loopend:;
 	}
 	if (kwstr == NULL)
diff --git a/date.y b/date.y
--- a/date.y
+++ b/date.y
@@ -13,9 +13,9 @@
 */
 /* SUPPRESS 287 on yaccpar_sccsid *//* Unused static variable */
 /* SUPPRESS 288 on yyerrlab *//* Label unused */
 
-#include <sys/timeb.h>
+/* #include <sys/timeb.h> */
 
 #include <ctype.h>
 #include <err.h>
 #include <string.h>
diff --git a/diff.c b/diff.c
--- a/diff.c
+++ b/diff.c
@@ -426,10 +426,10 @@ files_differ(FILE *f1, FILE *f2)
 static void
 prepare(int i, FILE *fd, off_t filesize, int flags)
 {
 	struct line *p;
-	int j, h;
-	size_t sz;
+	int h;
+	size_t j, sz;
 
 	rewind(fd);
 
 	sz = (filesize <= SIZE_MAX ? filesize : SIZE_MAX) / 25;
@@ -1141,9 +1141,9 @@ asciifile(FILE *f)
 	cnt = fread(buf, 1, sizeof(buf), f);
 	return (memchr(buf, '\0', cnt) == NULL);
 }
 
-#define begins_with(s, pre) (strncmp(s, pre, sizeof(pre)-1) == 0)
+#define begins_with(s, pre) (strncmp((const char *)s, pre, sizeof(pre)-1) == 0)
 
 static char *
 match_function(const long *f, int pos, FILE *fp)
 {
@@ -1160,9 +1160,9 @@ match_function(const long *f, int pos, F
 			nc = sizeof(buf) - 1;
 		nc = fread(buf, 1, nc, fp);
 		if (nc > 0) {
 			buf[nc] = '\0';
-			buf[strcspn(buf, "\n")] = '\0';
+			buf[strcspn((const char *)buf, "\n")] = '\0';
 			if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$') {
 				if (begins_with(buf, "private:")) {
 					if (!state)
 						state = " (private)";
@@ -1172,9 +1172,9 @@ match_function(const long *f, int pos, F
 				} else if (begins_with(buf, "public:")) {
 					if (!state)
 						state = " (public)";
 				} else {
-					if (strlcpy(lastbuf, buf,
+					if (strlcpy(lastbuf, (const char *)buf,
 					    sizeof(lastbuf)) >= sizeof(lastbuf))
 						errx(1,
 						    "match_function: strlcpy");
 					lastmatchline = pos;
diff --git a/diff3.c b/diff3.c
--- a/diff3.c
+++ b/diff3.c
@@ -455,9 +455,9 @@ ed_patch_lines(struct rcs_lines *dlines,
 		lp->l_line[lp->l_len - 1] = '\0';
 
 		/* len - 1 is NUL terminator so we use len - 2 for 'op' */
 		op = lp->l_line[lp->l_len - 2];
-		start = (int)strtol(lp->l_line, &ep, 10);
+		start = (int)strtol((const char *)lp->l_line, &ep, 10);
 
 		/* Restore the last byte of the buffer */
 		lp->l_line[lp->l_len - 1] = tmp;
 
@@ -896,9 +896,10 @@ edit(struct diff *diff, int fdup, int j)
 /* regurgitate */
 static int
 edscript(int n)
 {
-	int j, k;
+	int k;
+	size_t j;
 	char block[BUFSIZ+1];
 
 	for (; n > 0; n--) {
 		if (!oflag || !overlap[n])
diff --git a/rcs.c b/rcs.c
--- a/rcs.c
+++ b/rcs.c
@@ -802,9 +802,9 @@ rcs_patch_lines(struct rcs_lines *dlines
 		op = *(lp->l_line);
 		/* NUL-terminate line buffer for strtol() safety. */
 		tmp = lp->l_line[lp->l_len - 1];
 		lp->l_line[lp->l_len - 1] = '\0';
-		lineno = (int)strtol((lp->l_line + 1), &ep, 10);
+		lineno = (int)strtol((const char *)(lp->l_line + 1), &ep, 10);
 		if (lineno > dlines->l_nblines || lineno < 0 ||
 		    *ep != ' ')
 			errx(1, "invalid line specification in RCS patch");
 		ep++;
@@ -1050,9 +1050,9 @@ rcs_delta_stats(struct rcs_delta *rdp, i
 			op = *(lp->l_line);
 			/* NUL-terminate line buffer for strtol() safety. */
 			tmp = lp->l_line[lp->l_len - 1];
 			lp->l_line[lp->l_len - 1] = '\0';
-			(void)strtol((lp->l_line + 1), &ep, 10);
+			(void)strtol((const char *)(lp->l_line + 1), &ep, 10);
 			ep++;
 			nbln = (int)strtol(ep, &ep, 10);
 			/* Restore the last byte of the buffer */
 			lp->l_line[lp->l_len - 1] = tmp;
diff --git a/rcs.h b/rcs.h
--- a/rcs.h
+++ b/rcs.h
@@ -29,8 +29,9 @@
 
 #include <sys/queue.h>
 
 #include <stdio.h>
+#include <time.h>
 
 #include "buf.h"
 
 #define RCS_DIFF_MAXARG		32
diff --git a/rcsparse.c b/rcsparse.c
--- a/rcsparse.c
+++ b/rcsparse.c
@@ -29,8 +29,13 @@
 #include "rcs.h"
 #include "rcsparse.h"
 #include "xmalloc.h"
 
+#if !defined(_PW_NAME_LEN)
+#include <sys/param.h>
+#define _PW_NAME_LEN (MAXLOGNAME-1)
+#endif
+
 #define RCS_BUFSIZE	16384
 #define RCS_BUFEXTSIZE	8192
 
 /* RCS token types */
@@ -602,9 +607,9 @@ rcsparse_text(RCSFILE *rfp, struct rcs_p
 		return (1);
 
 	pdp->rp_delta->rd_tlen = pdp->rp_tlen - 1;
 	if (pdp->rp_delta->rd_tlen == 0) {
-		pdp->rp_delta->rd_text = xstrdup("");
+		pdp->rp_delta->rd_text = (u_char *) xstrdup("");
 	} else {
 		pdp->rp_delta->rd_text = xmalloc(pdp->rp_delta->rd_tlen);
 		memcpy(pdp->rp_delta->rd_text, pdp->rp_buf,
 		    pdp->rp_delta->rd_tlen);
@@ -1219,9 +1224,9 @@ valid_login(char *login_name)
 	/* The first character cannot be a hyphen */
 	if (*login_name == '-')
 		return 0;
 
-	for (cp = login_name ; *cp ; cp++) {
+	for (cp = (u_char *)login_name ; *cp ; cp++) {
 		/* We allow '$' as the last character for samba */
 		if (!isalnum(*cp) && *cp != '.' && *cp != '_' && *cp != '-' &&
 		    !(*cp == '$' && *(cp + 1) == '\0')) {
 			return 0;
@@ -1237,9 +1242,9 @@ valid_commitid(char *commitid)
 {
 	unsigned char *cp;
 
 	/* A-Za-z0-9 */
-	for (cp = commitid; *cp ; cp++) {
+	for (cp = (u_char *)commitid; *cp ; cp++) {
 		if (!isalnum(*cp))
 			return 0;
 	}
 	if ((char *)cp - commitid > RCS_COMMITID_MAXLEN)
diff --git a/rlog.c b/rlog.c
--- a/rlog.c
+++ b/rlog.c
@@ -340,9 +340,9 @@ rlog_select_daterev(RCSFILE *rcsfile, ch
 static void
 rlog_file(const char *fname, RCSFILE *file)
 {
 	char numb[RCS_REV_BUFSZ];
-	u_int nrev;
+	int nrev;
 	struct rcs_sym *sym;
 	struct rcs_access *acp;
 	struct rcs_delta *rdp;
 	struct rcs_lock *lkp;
@@ -355,10 +355,14 @@ rlog_file(const char *fname, RCSFILE *fi
 			errx(1, "invalid date: %s", rlog_dates);
 	} else
 		nrev = file->rf_ndelta;
 
+#if 0
 	if ((workfile = basename(fname)) == NULL)
 		err(1, "basename");
+#else
+	workfile = (char *)fname;
+#endif
 
 	/*
 	 * In case they specified 'foo,v' as argument.
 	 */
diff --git a/xmalloc.c b/xmalloc.c
--- a/xmalloc.c
+++ b/xmalloc.c
@@ -21,8 +21,12 @@
 #include <string.h>
 
 #include "xmalloc.h"
 
+#if !defined(u_long)
+#define u_long unsigned long
+#endif
+
 void *
 xmalloc(size_t size)
 {
 	void *ptr;
diff --git a/xmalloc.h b/xmalloc.h
--- a/xmalloc.h
+++ b/xmalloc.h
@@ -18,8 +18,13 @@
 
 #ifndef XMALLOC_H
 #define XMALLOC_H
 
+#if !defined(SIZE_MAX)
+#include <sys/limits.h>
+#define SIZE_MAX OFF_MAX
+#endif
+
 void	*xmalloc(size_t);
 void	*xcalloc(size_t, size_t);
 void	*xrealloc(void *, size_t, size_t);
 void     xfree(void *);