diff --git a/libc/regex/engine.c b/libc/regex/engine.c
index 66be3c7..eae6ff2 100644
--- a/libc/regex/engine.c
+++ b/libc/regex/engine.c
@@ -209,7 +209,7 @@
 			STATETEARDOWN(m);
 			return(REG_ESPACE);
 		}
-		for (i = 1; i <= m->g->nsub; i++)
+		for (i = 1; i <= (int)m->g->nsub; i++)
 			m->pmatch[i].rm_so = m->pmatch[i].rm_eo = -1;
 		if (!g->backrefs && !(m->eflags&REG_BACKR)) {
 			NOTE("dissecting");
@@ -267,8 +267,8 @@
 	}
 	if (nmatch > 1) {
 		assert(m->pmatch != NULL);
-		for (i = 1; i < nmatch; i++)
-			if (i <= m->g->nsub)
+		for (i = 1; i < (ssize_t)nmatch; i++)
+			if (i <= (int)m->g->nsub)
 				pmatch[i] = m->pmatch[i];
 			else {
 				pmatch[i].rm_so = -1;
diff --git a/libc/regex/regcomp.c b/libc/regex/regcomp.c
index 5b632c8..19f4790 100644
--- a/libc/regex/regcomp.c
+++ b/libc/regex/regcomp.c
@@ -249,8 +249,8 @@
 p_ere(struct parse *p, int stop)	/* character this ERE should end at */
 {
 	char c;
-	sopno prevback;
-	sopno prevfwd;
+	sopno prevback = 0;
+	sopno prevfwd = 0;
 	sopno conc;
 	int first = 1;		/* is this the first alternative? */
 
@@ -767,7 +767,7 @@
 p_b_cclass(struct parse *p, cset *cs)
 {
 	char *sp = p->next;
-	struct cclass *cp;
+	const struct cclass *cp;
 	size_t len;
 	char *u;
 	char c;
@@ -831,7 +831,7 @@
     int endc)			/* name ended by endc,']' */
 {
 	char *sp = p->next;
-	struct cname *cp;
+	const struct cname *cp;
 	int len;
 
 	while (MORE() && !SEETWO(endc, ']'))
@@ -1084,7 +1084,7 @@
 	cset *top = &p->g->sets[p->g->ncsets];
 	size_t css = (size_t)p->g->csetsize;
 
-	for (i = 0; i < css; i++)
+	for (i = 0; i < (ssize_t)css; i++)
 		CHsub(cs, i);
 	if (cs == top-1)	/* recover only the easy case */
 		p->g->ncsets--;
@@ -1112,10 +1112,10 @@
 	for (cs2 = &p->g->sets[0]; cs2 < top; cs2++)
 		if (cs2->hash == h && cs2 != cs) {
 			/* maybe */
-			for (i = 0; i < css; i++)
+			for (i = 0; i < (ssize_t)css; i++)
 				if (!!CHIN(cs2, i) != !!CHIN(cs, i))
 					break;		/* no */
-			if (i == css)
+			if (i == (ssize_t)css)
 				break;			/* yes */
 		}
 
@@ -1136,7 +1136,7 @@
 	int i;
 	size_t css = (size_t)p->g->csetsize;
 
-	for (i = 0; i < css; i++)
+	for (i = 0; i < (ssize_t)css; i++)
 		if (CHIN(cs, i))
 			return((char)i);
 	assert(never);
@@ -1153,7 +1153,7 @@
 	size_t css = (size_t)p->g->csetsize;
 	int n = 0;
 
-	for (i = 0; i < css; i++)
+	for (i = 0; i < (ssize_t)css; i++)
 		if (CHIN(cs, i))
 			n++;
 	return(n);
@@ -1412,7 +1412,7 @@
 findmust(struct parse *p, struct re_guts *g)
 {
 	sop *scan;
-	sop *start;    /* start initialized in the default case, after that */
+	sop *start = NULL;    /* start initialized in the default case, after that */
 	sop *newstart; /* newstart was initialized in the OCHAR case */
 	sopno newlen;
 	sop s;
diff --git a/libc/regex/regerror.c b/libc/regex/regerror.c
index 894a939..838ec8f 100644
--- a/libc/regex/regerror.c
+++ b/libc/regex/regerror.c
@@ -78,7 +78,7 @@
 size_t
 regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
 {
-	struct rerr *r;
+	const struct rerr *r;
 	size_t len;
 	int target = errcode &~ REG_ITOA;
 	char *s;
@@ -117,7 +117,7 @@
 static char *
 regatoi(const regex_t *preg, char *localbuf, int localbufsize)
 {
-	struct rerr *r;
+	const struct rerr *r;
 
 	for (r = rerrs; r->code != 0; r++)
 		if (strcmp(r->name, preg->re_endp) == 0)
diff --git a/libc/regex/regexec.c b/libc/regex/regexec.c
index 7b3bfc7..6feed3b 100644
--- a/libc/regex/regexec.c
+++ b/libc/regex/regexec.c
@@ -153,7 +153,7 @@
 		return(REG_BADPAT);
 	eflags = GOODFLAGS(eflags);
 
-	if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
+	if (g->nstates <= (int)(CHAR_BIT*sizeof(states1)) && !(eflags&REG_LARGE))
 		return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
 	else
 		return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));