diff --git a/include/common/regex.h b/include/common/regex.h
index c3b921b..0814f8f 100644
--- a/include/common/regex.h
+++ b/include/common/regex.h
@@ -88,7 +88,7 @@
  *
  * The function return 1 is succes case, else return 0 and err is filled.
  */
-int regex_comp(const char *str, struct my_regex *regex, int cs, int cap, char **err);
+struct my_regex *regex_comp(const char *str, int cs, int cap, char **err);
 int exp_replace(char *dst, unsigned int dst_size, char *src, const char *str, const regmatch_t *matches);
 const char *check_replace_string(const char *str);
 const char *chain_regex(struct hdr_exp **head, struct my_regex *preg,
@@ -161,6 +161,8 @@
                       size_t nmatch, regmatch_t pmatch[], int flags);
 
 static inline void regex_free(struct my_regex *preg) {
+	if (!preg)
+		return;
 #if defined(USE_PCRE) || defined(USE_PCRE_JIT)
 	pcre_free(preg->reg);
 /* PCRE < 8.20 requires pcre_free() while >= 8.20 requires pcre_study_free(),
@@ -176,6 +178,7 @@
 #else
 	regfree(&preg->regex);
 #endif
+	free(preg);
 }
 
 #endif /* _COMMON_REGEX_H */
diff --git a/include/types/action.h b/include/types/action.h
index 6c5fccf..948e281 100644
--- a/include/types/action.h
+++ b/include/types/action.h
@@ -121,7 +121,7 @@
 			char *name;            /* header name */
 			int name_len;          /* header name's length */
 			struct list fmt;       /* log-format compatible expression */
-			struct my_regex re;    /* used by replace-header and replace-value */
+			struct my_regex *re;   /* used by replace-header and replace-value */
 		} hdr_add;                     /* args used by "add-header" and "set-header" */
 		struct {
 			char *name;            /* header name */
diff --git a/include/types/hlua.h b/include/types/hlua.h
index 36554e2..70c7685 100644
--- a/include/types/hlua.h
+++ b/include/types/hlua.h
@@ -6,6 +6,7 @@
 #include <lua.h>
 #include <lauxlib.h>
 
+#include <common/regex.h>
 #include <common/xref.h>
 
 #include <types/proto_http.h>
diff --git a/src/cfgparse-listen.c b/src/cfgparse-listen.c
index b46e119..7760d9c 100644
--- a/src/cfgparse-listen.c
+++ b/src/cfgparse-listen.c
@@ -275,17 +275,10 @@
 	                                  ((px->cap & PR_CAP_BE) ? SMP_VAL_BE_HRS_HDR : SMP_VAL_FE_HRS_HDR),
 	                                  file, line);
 
-	preg = calloc(1, sizeof(*preg));
-	if (!preg) {
-		ha_alert("parsing [%s:%d] : '%s' : not enough memory to build regex.\n", file, line, cmd);
-		ret_code = ERR_ALERT | ERR_FATAL;
-		goto err;
-	}
-
 	cs = !(flags & REG_ICASE);
 	cap = !(flags & REG_NOSUB);
 	error = NULL;
-	if (!regex_comp(reg, preg, cs, cap, &error)) {
+	if (!(preg = regex_comp(reg, cs, cap, &error))) {
 		ha_alert("parsing [%s:%d] : '%s' : regular expression '%s' : %s\n", file, line, cmd, reg, error);
 		free(error);
 		ret_code = ERR_ALERT | ERR_FATAL;
@@ -309,7 +302,6 @@
  err_free:
 	regex_free(preg);
  err:
-	free(preg);
 	free(errmsg);
 	return ret_code;
 }
@@ -444,8 +436,14 @@
 				curproxy->expect_str = strdup(defproxy.expect_str);
 				if (defproxy.expect_regex) {
 					/* note: this regex is known to be valid */
-					curproxy->expect_regex = calloc(1, sizeof(*curproxy->expect_regex));
-					regex_comp(defproxy.expect_str, curproxy->expect_regex, 1, 1, NULL);
+					error = NULL;
+					if (!(curproxy->expect_regex = regex_comp(defproxy.expect_str, 1, 1, &error))) {
+						ha_alert("parsing [%s:%d] : regular expression '%s' : %s\n", file, linenum,
+						         defproxy.expect_str, error);
+						free(error);
+						err_code |= ERR_ALERT | ERR_FATAL;
+						goto out;
+					}
 				}
 			}
 
@@ -631,11 +629,8 @@
 		free(defproxy.server_id_hdr_name);
 		defproxy.server_id_hdr_len = 0;
 		free(defproxy.expect_str);
-		if (defproxy.expect_regex) {
-			regex_free(defproxy.expect_regex);
-			free(defproxy.expect_regex);
-			defproxy.expect_regex = NULL;
-		}
+		regex_free(defproxy.expect_regex);
+		defproxy.expect_regex = NULL;
 
 		if (defproxy.conf.logformat_string != default_http_log_format &&
 		    defproxy.conf.logformat_string != default_tcp_log_format &&
@@ -2927,16 +2922,11 @@
 				}
 				curproxy->options2 |= PR_O2_EXP_RSTS;
 				free(curproxy->expect_str);
-				if (curproxy->expect_regex) {
-					regex_free(curproxy->expect_regex);
-					free(curproxy->expect_regex);
-					curproxy->expect_regex = NULL;
-				}
+				regex_free(curproxy->expect_regex);
 				curproxy->expect_str = strdup(args[cur_arg + 1]);
-				curproxy->expect_regex = calloc(1, sizeof(*curproxy->expect_regex));
 				error = NULL;
-				if (!regex_comp(args[cur_arg + 1], curproxy->expect_regex, 1, 1, &error)) {
-					ha_alert("parsing [%s:%d] : '%s %s %s' : bad regular expression '%s': %s.\n",
+				if (!(curproxy->expect_regex = regex_comp(args[cur_arg + 1], 1, 1, &error))) {
+					ha_alert("parsing [%s:%d] : '%s %s %s' : regular expression '%s': %s.\n",
 						 file, linenum, args[0], args[1], ptr_arg, args[cur_arg + 1], error);
 					free(error);
 					err_code |= ERR_ALERT | ERR_FATAL;
@@ -2952,16 +2942,11 @@
 				}
 				curproxy->options2 |= PR_O2_EXP_RSTR;
 				free(curproxy->expect_str);
-				if (curproxy->expect_regex) {
-					regex_free(curproxy->expect_regex);
-					free(curproxy->expect_regex);
-					curproxy->expect_regex = NULL;
-				}
+				regex_free(curproxy->expect_regex);
 				curproxy->expect_str = strdup(args[cur_arg + 1]);
-				curproxy->expect_regex = calloc(1, sizeof(*curproxy->expect_regex));
 				error = NULL;
-				if (!regex_comp(args[cur_arg + 1], curproxy->expect_regex, 1, 1, &error)) {
-					ha_alert("parsing [%s:%d] : '%s %s %s' : bad regular expression '%s': %s.\n",
+				if (!(curproxy->expect_regex = regex_comp(args[cur_arg + 1], 1, 1, &error))) {
+					ha_alert("parsing [%s:%d] : '%s %s %s' : regular expression '%s': %s.\n",
 						 file, linenum, args[0], args[1], ptr_arg, args[cur_arg + 1], error);
 					free(error);
 					err_code |= ERR_ALERT | ERR_FATAL;
@@ -3258,10 +3243,9 @@
 				tcpcheck->action = TCPCHK_ACT_EXPECT;
 				tcpcheck->string_len = 0;
 				tcpcheck->string = NULL;
-				tcpcheck->expect_regex = calloc(1, sizeof(*tcpcheck->expect_regex));
 				error = NULL;
-				if (!regex_comp(args[cur_arg + 1], tcpcheck->expect_regex, 1, 1, &error)) {
-					ha_alert("parsing [%s:%d] : '%s %s %s' : bad regular expression '%s': %s.\n",
+				if (!(tcpcheck->expect_regex = regex_comp(args[cur_arg + 1], 1, 1, &error))) {
+					ha_alert("parsing [%s:%d] : '%s %s %s' : regular expression '%s': %s.\n",
 						 file, linenum, args[0], args[1], ptr_arg, args[cur_arg + 1], error);
 					free(error);
 					err_code |= ERR_ALERT | ERR_FATAL;
diff --git a/src/checks.c b/src/checks.c
index a7b4b2f..e6b0bd1 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -3193,8 +3193,7 @@
 		LIST_DEL(&rule->list);
 		free(rule->comment);
 		free(rule->string);
-		if (rule->expect_regex)
-			regex_free(rule->expect_regex);
+		regex_free(rule->expect_regex);
 		pool_free(pool_head_tcpcheck_rule, rule);
 	}
 	pool_free(pool_head_email_alert, alert);
diff --git a/src/haproxy.c b/src/haproxy.c
index bf91c0b..318ebf2 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -2168,11 +2168,7 @@
 		}
 
 		for (exp = p->req_exp; exp != NULL; ) {
-			if (exp->preg) {
-				regex_free(exp->preg);
-				free(exp->preg);
-			}
-
+			regex_free(exp->preg);
 			free((char *)exp->replace);
 			expb = exp;
 			exp = exp->next;
@@ -2180,11 +2176,7 @@
 		}
 
 		for (exp = p->rsp_exp; exp != NULL; ) {
-			if (exp->preg) {
-				regex_free(exp->preg);
-				free(exp->preg);
-			}
-
+			regex_free(exp->preg);
 			free((char *)exp->replace);
 			expb = exp;
 			exp = exp->next;
diff --git a/src/hlua.c b/src/hlua.c
index ff5ffba..a7fd52b 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -5366,13 +5366,13 @@
 	const char *name = MAY_LJMP(luaL_checklstring(L, 2, &name_len));
 	const char *reg = MAY_LJMP(luaL_checkstring(L, 3));
 	const char *value = MAY_LJMP(luaL_checkstring(L, 4));
-	struct my_regex re;
+	struct my_regex *re;
 
-	if (!regex_comp(reg, &re, 1, 1, NULL))
+	if (!(re = regex_comp(reg, 1, 1, NULL)))
 		WILL_LJMP(luaL_argerror(L, 3, "invalid regex"));
 
-	http_transform_header_str(htxn->s, msg, name, name_len, value, &re, action);
-	regex_free(&re);
+	http_transform_header_str(htxn->s, msg, name, name_len, value, re, action);
+	regex_free(re);
 	return 0;
 }
 
diff --git a/src/hlua_fcn.c b/src/hlua_fcn.c
index 60882f3..3b71ce1 100644
--- a/src/hlua_fcn.c
+++ b/src/hlua_fcn.c
@@ -1537,14 +1537,14 @@
 	return 1;
 }
 
-static struct my_regex *hlua_check_regex(lua_State *L, int ud)
+static struct my_regex **hlua_check_regex(lua_State *L, int ud)
 {
 	return (hlua_checkudata(L, ud, class_regex_ref));
 }
 
 static int hlua_regex_comp(struct lua_State *L)
 {
-	struct my_regex *regex;
+	struct my_regex **regex;
 	const char *str;
 	int cs;
 	char *err;
@@ -1556,7 +1556,7 @@
 	regex = lua_newuserdata(L, sizeof(*regex));
 
 	err = NULL;
-	if (!regex_comp(str, regex, cs, 1, &err)) {
+	if (!(*regex = regex_comp(str, cs, 1, &err))) {
 		lua_pushboolean(L, 0); /* status error */
 		lua_pushstring(L, err); /* Reason */
 		free(err);
@@ -1576,7 +1576,7 @@
 
 static int hlua_regex_exec(struct lua_State *L)
 {
-	struct my_regex *regex;
+	struct my_regex **regex;
 	const char *str;
 	size_t len;
 	struct buffer *tmp;
@@ -1584,6 +1584,11 @@
 	regex = hlua_check_regex(L, 1);
 	str = luaL_checklstring(L, 2, &len);
 
+	if (!*regex) {
+		lua_pushboolean(L, 0);
+		return 1;
+	}
+
 	/* Copy the string because regex_exec2 require a 'char *'
 	 * and not a 'const char *'.
 	 */
@@ -1594,14 +1599,14 @@
 	}
 	memcpy(tmp->area, str, len);
 
-	lua_pushboolean(L, regex_exec2(regex, tmp->area, len));
+	lua_pushboolean(L, regex_exec2(*regex, tmp->area, len));
 
 	return 1;
 }
 
 static int hlua_regex_match(struct lua_State *L)
 {
-	struct my_regex *regex;
+	struct my_regex **regex;
 	const char *str;
 	size_t len;
 	regmatch_t pmatch[20];
@@ -1612,6 +1617,11 @@
 	regex = hlua_check_regex(L, 1);
 	str = luaL_checklstring(L, 2, &len);
 
+	if (!*regex) {
+		lua_pushboolean(L, 0);
+		return 1;
+	}
+
 	/* Copy the string because regex_exec2 require a 'char *'
 	 * and not a 'const char *'.
 	 */
@@ -1622,7 +1632,7 @@
 	}
 	memcpy(tmp->area, str, len);
 
-	ret = regex_exec_match2(regex, tmp->area, len, 20, pmatch, 0);
+	ret = regex_exec_match2(*regex, tmp->area, len, 20, pmatch, 0);
 	lua_pushboolean(L, ret);
 	lua_newtable(L);
 	if (ret) {
@@ -1636,10 +1646,11 @@
 
 static int hlua_regex_free(struct lua_State *L)
 {
-	struct my_regex *regex;
+	struct my_regex **regex;
 
 	regex = hlua_check_regex(L, 1);
-	regex_free(regex);
+	regex_free(*regex);
+	*regex = NULL;
 	return 0;
 }
 
diff --git a/src/http_rules.c b/src/http_rules.c
index c7b5a71..ab01f26 100644
--- a/src/http_rules.c
+++ b/src/http_rules.c
@@ -263,7 +263,7 @@
 		LIST_INIT(&rule->arg.hdr_add.fmt);
 
 		error = NULL;
-		if (!regex_comp(args[cur_arg + 1], &rule->arg.hdr_add.re, 1, 1, &error)) {
+		if (!(rule->arg.hdr_add.re = regex_comp(args[cur_arg + 1], 1, 1, &error))) {
 			ha_alert("parsing [%s:%d] : '%s' : %s.\n", file, linenum,
 				 args[cur_arg + 1], error);
 			free(error);
@@ -713,7 +713,7 @@
 		LIST_INIT(&rule->arg.hdr_add.fmt);
 
 		error = NULL;
-		if (!regex_comp(args[cur_arg + 1], &rule->arg.hdr_add.re, 1, 1, &error)) {
+		if (!(rule->arg.hdr_add.re = regex_comp(args[cur_arg + 1], 1, 1, &error))) {
 			ha_alert("parsing [%s:%d] : '%s' : %s.\n", file, linenum,
 				 args[cur_arg + 1], error);
 			free(error);
@@ -1191,7 +1191,7 @@
 
 	list_for_each_entry_safe(pr, tr, r, list) {
 		LIST_DEL(&pr->list);
-		regex_free(&pr->arg.hdr_add.re);
+		regex_free(pr->arg.hdr_add.re);
 		free(pr);
 	}
 }
@@ -1205,7 +1205,7 @@
 		if (pr->action == ACT_HTTP_REQ_AUTH)
 			free(pr->arg.auth.realm);
 
-		regex_free(&pr->arg.hdr_add.re);
+		regex_free(pr->arg.hdr_add.re);
 		free(pr);
 	}
 }
diff --git a/src/pattern.c b/src/pattern.c
index 49d05a1..c93be9b 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -1142,7 +1142,6 @@
 
 	list_for_each_entry_safe(pat, tmp, &expr->patterns, list) {
 		regex_free(pat->pat.ptr.ptr);
-		free(pat->pat.ptr.ptr);
 		free(pat->pat.data);
 		free(pat);
 	}
@@ -1253,18 +1252,9 @@
 	/* duplicate pattern */
 	memcpy(&patl->pat, pat, sizeof(*pat));
 
-	/* allocate regex */
-	patl->pat.ptr.reg = calloc(1, sizeof(*patl->pat.ptr.reg));
-	if (!patl->pat.ptr.reg) {
-		free(patl);
-		memprintf(err, "out of memory while indexing pattern");
-		return 0;
-	}
-
 	/* compile regex */
-	if (!regex_comp(pat->ptr.str, patl->pat.ptr.reg,
-	                !(expr->mflags & PAT_MF_IGNORE_CASE), cap, err)) {
-		free(patl->pat.ptr.reg);
+	if (!(patl->pat.ptr.reg = regex_comp(pat->ptr.str, !(expr->mflags & PAT_MF_IGNORE_CASE),
+	                                     cap, err))) {
 		free(patl);
 		return 0;
 	}
@@ -1562,7 +1552,6 @@
 		/* Delete and free entry. */
 		LIST_DEL(&pat->list);
 		regex_free(pat->pat.ptr.ptr);
-		free(pat->pat.ptr.ptr);
 		free(pat->pat.data);
 		free(pat);
 	}
diff --git a/src/proto_http.c b/src/proto_http.c
index 2ab3315..b47fbe6 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -1581,7 +1581,7 @@
 			if (http_transform_header(s, &txn->req, rule->arg.hdr_add.name,
 			                          rule->arg.hdr_add.name_len,
 			                          &rule->arg.hdr_add.fmt,
-			                          &rule->arg.hdr_add.re, rule->action)) {
+			                          rule->arg.hdr_add.re, rule->action)) {
 				rule_ret = HTTP_RULE_RES_BADREQ;
 				goto end;
 			}
@@ -1939,7 +1939,7 @@
 			if (http_transform_header(s, &txn->rsp, rule->arg.hdr_add.name,
 			                          rule->arg.hdr_add.name_len,
 			                          &rule->arg.hdr_add.fmt,
-			                          &rule->arg.hdr_add.re, rule->action)) {
+			                          rule->arg.hdr_add.re, rule->action)) {
 				rule_ret = HTTP_RULE_RES_BADREQ;
 				goto end;
 			}
diff --git a/src/proto_htx.c b/src/proto_htx.c
index 2d1d8fb..b99b9cf 100644
--- a/src/proto_htx.c
+++ b/src/proto_htx.c
@@ -2901,7 +2901,7 @@
 				if (htx_transform_header(s, &s->req, htx,
 							 ist2(rule->arg.hdr_add.name, rule->arg.hdr_add.name_len),
 							 &rule->arg.hdr_add.fmt,
-							 &rule->arg.hdr_add.re, rule->action)) {
+							 rule->arg.hdr_add.re, rule->action)) {
 					rule_ret = HTTP_RULE_RES_BADREQ;
 					goto end;
 				}
@@ -3243,7 +3243,7 @@
 				if (htx_transform_header(s, &s->res, htx,
 							 ist2(rule->arg.hdr_add.name, rule->arg.hdr_add.name_len),
 							 &rule->arg.hdr_add.fmt,
-							 &rule->arg.hdr_add.re, rule->action)) {
+							 rule->arg.hdr_add.re, rule->action)) {
 					rule_ret = HTTP_RULE_RES_BADREQ;
 					goto end;
 				}
diff --git a/src/regex.c b/src/regex.c
index 713f0c9..6b86b03 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -337,13 +337,32 @@
 #endif
 }
 
-int regex_comp(const char *str, struct my_regex *regex, int cs, int cap, char **err)
+struct my_regex *regex_comp(const char *str, int cs, int cap, char **err)
 {
+	struct my_regex *regex = NULL;
 #if defined(USE_PCRE) || defined(USE_PCRE_JIT)
 	int flags = 0;
 	const char *error;
 	int erroffset;
+#elif defined(USE_PCRE2) || defined(USE_PCRE2_JIT)
+	int flags = 0;
+	int errn;
+#if defined(USE_PCRE2_JIT)
+	int jit;
+#endif
+	PCRE2_UCHAR error[256];
+	PCRE2_SIZE erroffset;
+#else
+	int flags = REG_EXTENDED;
+#endif
+
+	regex = calloc(1, sizeof(*regex));
+	if (!regex) {
+		memprintf(err, "not enough memory to build regex");
+		goto out_fail_alloc;
+	}
 
+#if defined(USE_PCRE) || defined(USE_PCRE_JIT)
 	if (!cs)
 		flags |= PCRE_CASELESS;
 	if (!cap)
@@ -352,24 +371,16 @@
 	regex->reg = pcre_compile(str, flags, &error, &erroffset, NULL);
 	if (!regex->reg) {
 		memprintf(err, "regex '%s' is invalid (error=%s, erroffset=%d)", str, error, erroffset);
-		return 0;
+		goto out_fail_alloc;
 	}
 
 	regex->extra = pcre_study(regex->reg, PCRE_STUDY_JIT_COMPILE, &error);
 	if (!regex->extra && error != NULL) {
 		pcre_free(regex->reg);
 		memprintf(err, "failed to compile regex '%s' (error=%s)", str, error);
-		return 0;
+		goto out_fail_alloc;
 	}
 #elif defined(USE_PCRE2) || defined(USE_PCRE2_JIT)
-	int flags = 0;
-	int errn;
-#if defined(USE_PCRE2_JIT)
-	int jit;
-#endif
-	PCRE2_UCHAR error[256];
-	PCRE2_SIZE erroffset;
-
 	if (!cs)
 		flags |= PCRE2_CASELESS;
 	if (!cap)
@@ -379,7 +390,7 @@
 	if (!regex->reg) {
 		pcre2_get_error_message(errn, error, sizeof(error));
 		memprintf(err, "regex '%s' is invalid (error=%s, erroffset=%zu)", str, error, erroffset);
-		return 0;
+		goto out_fail_alloc;
 	}
 
 #if defined(USE_PCRE2_JIT)
@@ -391,13 +402,11 @@
 	if (jit < 0 && jit != PCRE2_ERROR_JIT_BADOPTION) {
 		pcre2_code_free(regex->reg);
 		memprintf(err, "regex '%s' jit compilation failed", str);
-		return 0;
+		goto out_fail_alloc;
 	}
 #endif
 
 #else
-	int flags = REG_EXTENDED;
-
 	if (!cs)
 		flags |= REG_ICASE;
 	if (!cap)
@@ -405,10 +414,14 @@
 
 	if (regcomp(&regex->regex, str, flags) != 0) {
 		memprintf(err, "regex '%s' is invalid", str);
-		return 0;
+		goto out_fail_alloc;
 	}
 #endif
-	return 1;
+	return regex;
+
+  out_fail_alloc:
+	free(regex);
+	return NULL;
 }
 
 static void regex_register_build_options(void)
diff --git a/src/sample.c b/src/sample.c
index 2a1ce8d..67f59e8 100644
--- a/src/sample.c
+++ b/src/sample.c
@@ -1328,20 +1328,11 @@
 				continue;
 			}
 
-			reg = calloc(1, sizeof(*reg));
-			if (!reg) {
-				ha_alert("parsing [%s:%d] : not enough memory to build regex in arg %d of %s%s%s%s '%s' %s proxy '%s'.\n",
-					 cur->file, cur->line,
-					 cur->arg_pos + 1, conv_pre, conv_ctx, conv_pos, ctx, cur->kw, where, p->id);
-				cfgerr++;
-				continue;
-			}
-
 			rflags = 0;
 			rflags |= (arg->type_flags & ARGF_REG_ICASE) ? REG_ICASE : 0;
 			err = NULL;
 
-			if (!regex_comp(arg->data.str.area, reg, !(rflags & REG_ICASE), 1 /* capture substr */, &err)) {
+			if (!(reg = regex_comp(arg->data.str.area, !(rflags & REG_ICASE), 1 /* capture substr */, &err))) {
 				ha_alert("parsing [%s:%d] : error in regex '%s' in arg %d of %s%s%s%s '%s' %s proxy '%s' : %s.\n",
 					 cur->file, cur->line,
 					 arg->data.str.area,
@@ -1425,11 +1416,8 @@
 			p->unresolved = 0;
 		}
 		else if (p->type == ARGT_REG) {
-			if (p->data.reg) {
-				regex_free(p->data.reg);
-				free(p->data.reg);
-				p->data.reg = NULL;
-			}
+			regex_free(p->data.reg);
+			p->data.reg = NULL;
 		}
 		p++;
 	}