--- a/bsdiff.c
+++ b/bsdiff.c
@@ -101,7 +101,7 @@ static void split(off_t *I,off_t *V,off_
 	if(start+len>kk) split(I,V,kk,start+len-kk,h);
 }
 
-static void qsufsort(off_t *I,off_t *V,u_char *old,off_t oldsize)
+static void qsufsort(off_t *I,off_t *V,unsigned char *old,off_t oldsize)
 {
 	off_t buckets[256];
 	off_t i,h,len;
@@ -139,7 +139,7 @@ static void qsufsort(off_t *I,off_t *V,u
 	for(i=0;i<oldsize+1;i++) I[V[i]]=i;
 }
 
-static off_t matchlen(u_char *old,off_t oldsize,u_char *new,off_t newsize)
+static off_t matchlen(unsigned char *old,off_t oldsize,unsigned char *new,off_t newsize)
 {
 	off_t i;
 
@@ -149,8 +149,8 @@ static off_t matchlen(u_char *old,off_t
 	return i;
 }
 
-static off_t search(off_t *I,u_char *old,off_t oldsize,
-		u_char *new,off_t newsize,off_t st,off_t en,off_t *pos)
+static off_t search(off_t *I,unsigned char *old,off_t oldsize,
+		unsigned char *new,off_t newsize,off_t st,off_t en,off_t *pos)
 {
 	off_t x,y;
 
@@ -175,7 +175,7 @@ static off_t search(off_t *I,u_char *old
 	};
 }
 
-static void offtout(off_t x,u_char *buf)
+static void offtout(off_t x,unsigned char *buf)
 {
 	off_t y;
 
@@ -196,7 +196,7 @@ static void offtout(off_t x,u_char *buf)
 int main(int argc,char *argv[])
 {
 	int fd;
-	u_char *old,*new;
+	unsigned char *old,*new;
 	off_t oldsize,newsize;
 	off_t *I,*V;
 	off_t scan,pos,len;
@@ -206,9 +206,9 @@ int main(int argc,char *argv[])
 	off_t overlap,Ss,lens;
 	off_t i;
 	off_t dblen,eblen;
-	u_char *db,*eb;
-	u_char buf[8];
-	u_char header[32];
+	unsigned char *db,*eb;
+	unsigned char buf[8];
+	unsigned char header[32];
 	FILE * pf;
 	BZFILE * pfbz2;
 	int bz2err;
--- a/bspatch.c
+++ b/bspatch.c
@@ -36,7 +36,7 @@ __FBSDID("$FreeBSD: src/usr.bin/bsdiff/b
 #include <unistd.h>
 #include <fcntl.h>
 
-static off_t offtin(u_char *buf)
+static off_t offtin(unsigned char *buf)
 {
 	off_t y;
 
@@ -62,8 +62,8 @@ int main(int argc,char * argv[])
 	int fd;
 	ssize_t oldsize,newsize;
 	ssize_t bzctrllen,bzdatalen;
-	u_char header[32],buf[8];
-	u_char *old, *new;
+	unsigned char header[32],buf[8];
+	unsigned char *old, *new;
 	off_t oldpos,newpos;
 	off_t ctrl[3];
 	off_t lenread;