diff --git a/doc/configuration.txt b/doc/configuration.txt
index 6733e650b..596cfb5da 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -25739,6 +25739,14 @@ Flags are :
   * X: hexadecimal representation (IPs, Ports, %Ts, %rt, %pid)
   * E: escape characters '"', '\' and ']' in a string with '\' as prefix
        (intended purpose is for the RFC5424 structured-data log formats)
+  * bin: try to preserve binary data, this can be useful with sample
+         expressions that output binary data in order to preserve the original
+         data. Be careful however, because it can obviously generate non-
+         printable chars, including NULL-byte, which most syslog endpoints
+         don't expect. Thus it is mainly intended for use with set-var-fmt,
+         rings and binary-capable log endpoints.
+         This option can only be set globally (with %o), it will be ignored
+         if set on an individual node's options.
 
   Example:
 
diff --git a/include/haproxy/log-t.h b/include/haproxy/log-t.h
index 657454213..de6edab23 100644
--- a/include/haproxy/log-t.h
+++ b/include/haproxy/log-t.h
@@ -47,6 +47,7 @@
 #define LOG_OPT_HTTP            0x00000020
 #define LOG_OPT_ESC             0x00000040
 #define LOG_OPT_MERGE_SPACES    0x00000080
+#define LOG_OPT_BIN             0x00000100
 
 
 /* Fields that need to be extracted from the incoming connection or request for
diff --git a/src/log.c b/src/log.c
index 491304692..742d4a801 100644
--- a/src/log.c
+++ b/src/log.c
@@ -327,6 +327,7 @@ struct logformat_tag_args tag_args_list[] = {
 	{ "Q", LOG_OPT_QUOTE },
 	{ "X", LOG_OPT_HEXA },
 	{ "E", LOG_OPT_ESC },
+	{ "bin", LOG_OPT_BIN },
 	{  0,  0 }
 };
 
@@ -1748,8 +1749,10 @@ static inline void lf_buildctx_prepare(struct lf_buildctx *ctx,
 	if (node) {
 		/* per-node options are only considered if not already set
 		 * globally
+		 *
+		 * Also, ignore LOG_OPT_BIN since it is a global-only option
 		 */
-		ctx->options |= node->options;
+		ctx->options |= (node->options & ~LOG_OPT_BIN);
 
 		/* consider node's typecast setting */
 		ctx->typecast = node->typecast;
@@ -3237,18 +3240,35 @@ int sess_build_logline(struct session *sess, struct stream *s, char *dst, size_t
 
 				type = SMP_T_STR; // default
 
+				if (key && key->data.type == SMP_T_BIN &&
+				    (ctx.options & LOG_OPT_BIN)) {
+					/* output type is binary, and binary option is set:
+					 * preserve output type unless typecast is set to
+					 * force output type to string
+					 */
+					if (ctx.typecast != SMP_T_STR)
+						type = SMP_T_BIN;
+				}
+
 				if (key && !sample_convert(key, type))
 					key = NULL;
 
 				if (ctx.options & LOG_OPT_HTTP)
 					ret = lf_encode_chunk(tmplog, dst + maxsize,
 					                      '%', http_encode_map, key ? &key->data.u.str : &empty, &ctx);
-				else
-					ret = lf_text_len(tmplog,
-							  key ? key->data.u.str.area : NULL,
-							  key ? key->data.u.str.data : 0,
-							  dst + maxsize - tmplog,
-							  &ctx);
+				else {
+					if (key && type == SMP_T_BIN)
+						ret = lf_encode_chunk(tmplog, dst + maxsize,
+						                      0, no_escape_map,
+						                      &key->data.u.str,
+						                      &ctx);
+					else
+						ret = lf_text_len(tmplog,
+						                  key ? key->data.u.str.area : NULL,
+						                  key ? key->data.u.str.data : 0,
+						                  dst + maxsize - tmplog,
+						                  &ctx);
+				}
 				if (ret == NULL)
 					goto out;
 				tmplog = ret;