diff --git a/include/types/compression.h b/include/types/compression.h
index e4b1f273d..ae1e87df8 100644
--- a/include/types/compression.h
+++ b/include/types/compression.h
@@ -47,9 +47,19 @@ struct comp_ctx {
 	int cur_lvl;
 };
 
+/* Thanks to MSIE/IIS, the "deflate" name is ambigous, as according to the RFC
+ * it's a zlib-wrapped deflate stream, but MSIE only understands a raw deflate
+ * stream. For this reason some people prefer to emit a raw deflate stream on
+ * "deflate" and we'll need two algos for the same name, they are distinguished
+ * with the config name.
+ */
 struct comp_algo {
-	char *name;
-	int name_len;
+	char *cfg_name;  /* config name */
+	int cfg_name_len;
+
+	char *ua_name;  /* name for the user-agent */
+	int ua_name_len;
+
 	int (*init)(struct comp_ctx **comp_ctx, int level);
 	int (*add_data)(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out);
 	int (*flush)(struct comp_ctx *comp_ctx, struct buffer *out, int flag);
diff --git a/src/compression.c b/src/compression.c
index eadeb9d5f..8ddee57bd 100644
--- a/src/compression.c
+++ b/src/compression.c
@@ -73,12 +73,12 @@ static int deflate_end(struct comp_ctx **comp_ctx);
 
 const struct comp_algo comp_algos[] =
 {
-	{ "identity", 8, identity_init, identity_add_data, identity_flush, identity_reset, identity_end },
+	{ "identity",     8, "identity", 8, identity_init, identity_add_data, identity_flush, identity_reset, identity_end },
 #ifdef USE_ZLIB
-	{ "deflate",  7, deflate_init,  deflate_add_data,  deflate_flush,  deflate_reset,  deflate_end },
-	{ "gzip",     4, gzip_init,     deflate_add_data,  deflate_flush,  deflate_reset,  deflate_end },
+	{ "deflate",      7, "deflate",  7, deflate_init,  deflate_add_data,  deflate_flush,  deflate_reset,  deflate_end },
+	{ "gzip",         4, "gzip",     4, gzip_init,     deflate_add_data,  deflate_flush,  deflate_reset,  deflate_end },
 #endif /* USE_ZLIB */
-	{ NULL,       0, NULL ,         NULL,              NULL,           NULL,           NULL }
+	{ NULL,       0, NULL,          0, NULL ,         NULL,              NULL,           NULL,           NULL }
 };
 
 /*
@@ -104,8 +104,8 @@ int comp_append_algo(struct comp *comp, const char *algo)
 	struct comp_algo *comp_algo;
 	int i;
 
-	for (i = 0; comp_algos[i].name; i++) {
-		if (!strcmp(algo, comp_algos[i].name)) {
+	for (i = 0; comp_algos[i].cfg_name; i++) {
+		if (!strcmp(algo, comp_algos[i].cfg_name)) {
 			comp_algo = calloc(1, sizeof(struct comp_algo));
 			memmove(comp_algo, &comp_algos[i], sizeof(struct comp_algo));
 			comp_algo->next = comp->algos;
@@ -669,8 +669,8 @@ smp_fetch_res_comp_algo(struct proxy *px, struct session *l4, void *l7, unsigned
 
 	smp->type = SMP_T_STR;
 	smp->flags = SMP_F_CONST;
-	smp->data.str.str = l4->comp_algo->name;
-	smp->data.str.len = l4->comp_algo->name_len;
+	smp->data.str.str = l4->comp_algo->cfg_name;
+	smp->data.str.len = l4->comp_algo->cfg_name_len;
 	return 1;
 }
 
diff --git a/src/haproxy.c b/src/haproxy.c
index 07d67bebf..8063f37b9 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -262,8 +262,8 @@ void display_build_opts()
 	{
 		int i;
 
-		for (i = 0; comp_algos[i].name; i++) {
-			printf("%s %s", (i == 0 ? "" : ","), comp_algos[i].name);
+		for (i = 0; comp_algos[i].cfg_name; i++) {
+			printf("%s %s(\"%s\")", (i == 0 ? "" : ","), comp_algos[i].cfg_name, comp_algos[i].ua_name);
 		}
 		if (i == 0) {
 			printf("none");
diff --git a/src/proto_http.c b/src/proto_http.c
index 56e4d3f66..24de4abf3 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -2309,7 +2309,7 @@ int select_compression_request_header(struct session *s, struct buffer *req)
 
 			for (comp_algo = comp_algo_back; comp_algo; comp_algo = comp_algo->next) {
 				if (*(ctx.line + ctx.val) == '*' ||
-				    word_match(ctx.line + ctx.val, toklen, comp_algo->name, comp_algo->name_len)) {
+				    word_match(ctx.line + ctx.val, toklen, comp_algo->ua_name, comp_algo->ua_name_len)) {
 					s->comp_algo = comp_algo;
 					best_q = q;
 					break;
@@ -2333,7 +2333,7 @@ int select_compression_request_header(struct session *s, struct buffer *req)
 	/* identity is implicit does not require headers */
 	if ((s->be->comp && (comp_algo_back = s->be->comp->algos)) || (s->fe->comp && (comp_algo_back = s->fe->comp->algos))) {
 		for (comp_algo = comp_algo_back; comp_algo; comp_algo = comp_algo->next) {
-			if (comp_algo->name_len == 8 && memcmp(comp_algo->name, "identity", 8) == 0) {
+			if (comp_algo->cfg_name_len == 8 && memcmp(comp_algo->cfg_name, "identity", 8) == 0) {
 				s->comp_algo = comp_algo;
 				return 1;
 			}
@@ -2445,11 +2445,11 @@ int select_compression_response_header(struct session *s, struct buffer *res)
 	 * Accept-Encoding header, and SHOULD NOT be used in the Content-Encoding
 	 * header.
 	 */
-	if (s->comp_algo->name_len != 8 || memcmp(s->comp_algo->name, "identity", 8) != 0) {
+	if (s->comp_algo->cfg_name_len != 8 || memcmp(s->comp_algo->cfg_name, "identity", 8) != 0) {
 		trash.len = 18;
 		memcpy(trash.str, "Content-Encoding: ", trash.len);
-		memcpy(trash.str + trash.len, s->comp_algo->name, s->comp_algo->name_len);
-		trash.len += s->comp_algo->name_len;
+		memcpy(trash.str + trash.len, s->comp_algo->ua_name, s->comp_algo->ua_name_len);
+		trash.len += s->comp_algo->ua_name_len;
 		trash.str[trash.len] = '\0';
 		http_header_add_tail2(&txn->rsp, &txn->hdr_idx, trash.str, trash.len);
 	}