diff --git a/src/pattern.c b/src/pattern.c
index f851331..9787ecc 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -118,6 +118,8 @@
 
 /******************************************************************/
 /*          Pattern casts functions                               */
+/*   Note: these functions do *NOT* set the output type on the    */
+/*   sample, the caller is responsible for doing this on return.  */
 /******************************************************************/
 
 static int c_ip2int(struct sample *smp)
@@ -466,6 +468,10 @@
  * pattern is not found or when format conversion failed.
  *  If <p> is not null, function returns results in structure pointed by <p>.
  *  If <p> is null, functions returns a pointer on a static pattern structure.
+ *
+ * Note: the fetch functions are required to properly set the return type. The
+ * conversion functions must do so too. However the cast functions do not need
+ * to since they're made to cast mutiple types according to what is required.
  */
 struct sample *pattern_process(struct proxy *px, struct session *l4, void *l7, int dir,
                                struct pattern_expr *expr, struct sample *p)
@@ -479,23 +485,21 @@
 	if (!expr->fetch->process(px, l4, l7, dir, expr->arg_p, p))
 		return NULL;
 
-	p->type = expr->fetch->out_type;
-
 	list_for_each_entry(conv_expr, &expr->conv_exprs, list) {
 		if (!pattern_casts[p->type][conv_expr->conv->in_type](p))
 			return NULL;
 
+		/* force the output type after a cast */
 		p->type = conv_expr->conv->in_type;
 		if (!conv_expr->conv->process(conv_expr->arg_p, p))
 			return NULL;
-
-		p->type = conv_expr->conv->out_type;
 	}
 	return p;
 }
 
 /*****************************************************************/
 /*    Pattern format convert functions                           */
+/*    These functions set the data type on return.               */
 /*****************************************************************/
 
 static int pattern_conv_str2lower(const struct arg *arg_p, struct sample *smp)
@@ -509,6 +513,7 @@
 		if ((smp->data.str.str[i] >= 'A') && (smp->data.str.str[i] <= 'Z'))
 			smp->data.str.str[i] += 'a' - 'A';
 	}
+	smp->type = SMP_T_STR;
 	return 1;
 }
 
@@ -523,6 +528,7 @@
 		if ((smp->data.str.str[i] >= 'a') && (smp->data.str.str[i] <= 'z'))
 			smp->data.str.str[i] += 'A' - 'a';
 	}
+	smp->type = SMP_T_STR;
 	return 1;
 }
 
@@ -530,6 +536,7 @@
 static int pattern_conv_ipmask(const struct arg *arg_p, struct sample *smp)
 {
 	smp->data.ipv4.s_addr &= arg_p->data.ipv4.s_addr;
+	smp->type = SMP_T_IPV4;
 	return 1;
 }
 
diff --git a/src/proto_http.c b/src/proto_http.c
index 4d504b0..933351a 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -8352,6 +8352,7 @@
 {
 	struct http_txn *txn = l7;
 
+	smp->type = SMP_T_CSTR;
 	return http_get_hdr(&txn->req, arg_p->data.str.str, arg_p->data.str.len, &txn->hdr_idx,
 			    -1, NULL, &smp->data.str.str, &smp->data.str.len);
 }
@@ -8455,6 +8456,7 @@
 				  &url_param_value, &url_param_value_l))
 		return 0;
 
+	smp->type = SMP_T_CSTR;
 	smp->data.str.str = url_param_value;
 	smp->data.str.len = url_param_value_l;
 	return 1;
@@ -8508,6 +8510,7 @@
 				  arg_p->data.str.str, arg_p->data.str.len, 1,
 				  &cookie_value, &cookie_value_l);
 	if (found) {
+		smp->type = SMP_T_CSTR;
 		smp->data.str.str = cookie_value;
 		smp->data.str.len = cookie_value_l;
 	}
@@ -8530,6 +8533,7 @@
 				  arg_p->data.str.str, arg_p->data.str.len, 1,
 				  &cookie_value, &cookie_value_l);
 	if (found) {
+		smp->type = SMP_T_CSTR;
 		smp->data.str.str = cookie_value;
 		smp->data.str.len = cookie_value_l;
 	}
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index 6b2101a..bd46de2 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -1281,6 +1281,7 @@
 	if (l4->si[0].addr.from.ss_family != AF_INET )
 		return 0;
 
+	smp->type = SMP_T_IPV4;
 	smp->data.ipv4.s_addr = ((struct sockaddr_in *)&l4->si[0].addr.from)->sin_addr.s_addr;
 	return 1;
 }
@@ -1293,6 +1294,7 @@
 	if (l4->si[0].addr.from.ss_family != AF_INET6)
 		return 0;
 
+	smp->type = SMP_T_IPV6;
 	memcpy(smp->data.ipv6.s6_addr, ((struct sockaddr_in6 *)&l4->si[0].addr.from)->sin6_addr.s6_addr, sizeof(smp->data.ipv6.s6_addr));
 	return 1;
 }
@@ -1346,6 +1348,7 @@
 	if (l4->si[0].addr.to.ss_family != AF_INET)
 		return 0;
 
+	smp->type = SMP_T_IPV4;
 	smp->data.ipv4.s_addr = ((struct sockaddr_in *)&l4->si[0].addr.to)->sin_addr.s_addr;
 	return 1;
 }
@@ -1360,6 +1363,7 @@
 	if (l4->si[0].addr.to.ss_family != AF_INET6)
 		return 0;
 
+	smp->type = SMP_T_IPV6;
 	memcpy(smp->data.ipv6.s6_addr, ((struct sockaddr_in6 *)&l4->si[0].addr.to)->sin6_addr.s6_addr, sizeof(smp->data.ipv6.s6_addr));
 	return 1;
 }
@@ -1383,6 +1387,7 @@
 pattern_fetch_dport(struct proxy *px, struct session *l4, void *l7, int dir,
                     const struct arg *arg, struct sample *smp)
 {
+	smp->type = SMP_T_UINT;
 	stream_sock_get_to_addr(&l4->si[0]);
 
 	if (!(smp->data.uint = get_host_port(&l4->si[0].addr.to)))
@@ -1435,6 +1440,7 @@
 		return 0;
 
 	/* init chunk as read only */
+	smp->type = SMP_T_CBIN;
 	chunk_initlen(&smp->data.str, b->p + buf_offset, 0, buf_size);
 
 	return 1;
@@ -1460,6 +1466,7 @@
 		return 0;
 
 	/* init chunk as read only */
+	smp->type = SMP_T_CBIN;
 	chunk_initlen(&smp->data.str, b->p + buf_offset, 0, buf_size);
 
 	return 1;
@@ -1486,6 +1493,7 @@
 
 	expr.args = args;
 
+	/* type set by acl_fetch_rdp_cookie */
 	ret = acl_fetch_rdp_cookie(px, l4, NULL, ACL_DIR_REQ, &expr, smp);
 	if (ret == 0 || (smp->flags & SMP_F_MAY_CHANGE) || smp->data.str.len == 0)
 		return 0;