diff --git a/dev/flags/flags.c b/dev/flags/flags.c
index d867ba247..c587cab99 100644
--- a/dev/flags/flags.c
+++ b/dev/flags/flags.c
@@ -6,6 +6,7 @@
 #include <haproxy/fd-t.h>
 #include <haproxy/http_ana-t.h>
 #include <haproxy/htx-t.h>
+#include <haproxy/mux_h2-t.h>
 #include <haproxy/stconn-t.h>
 #include <haproxy/stream-t.h>
 #include <haproxy/task-t.h>
@@ -24,10 +25,12 @@
 #define SHOW_AS_HTX   0x00000400
 #define SHOW_AS_HMSG  0x00000800
 #define SHOW_AS_FD    0x00001000
+#define SHOW_AS_H2C   0x00002000
+#define SHOW_AS_H2S   0x00004000
 
 // command line names, must be in exact same order as the SHOW_AS_* flags above
 // so that show_as_words[i] matches flag 1U<<i.
-const char *show_as_words[] = { "ana", "chn", "conn", "sc", "stet", "strm", "task", "txn", "sd", "hsl", "htx", "hmsg", "fd", };
+const char *show_as_words[] = { "ana", "chn", "conn", "sc", "stet", "strm", "task", "txn", "sd", "hsl", "htx", "hmsg", "fd", "h2c", "h2s", };
 
 /* will be sufficient for even largest flag names */
 static char buf[4096];
@@ -134,6 +137,8 @@ int main(int argc, char **argv)
 		if (show_as & SHOW_AS_HTX)   printf("htx->flags = %s\n",  (htx_show_flags    (buf, bsz, " | ", flags), buf));
 		if (show_as & SHOW_AS_HMSG)  printf("hmsg->flags = %s\n", (hmsg_show_flags   (buf, bsz, " | ", flags), buf));
 		if (show_as & SHOW_AS_FD)    printf("fd->flags = %s\n",   (fd_show_flags     (buf, bsz, " | ", flags), buf));
+		if (show_as & SHOW_AS_H2C)   printf("h2c->flags = %s\n",  (h2c_show_flags    (buf, bsz, " | ", flags), buf));
+		if (show_as & SHOW_AS_H2S)   printf("h2s->flags = %s\n",  (h2s_show_flags    (buf, bsz, " | ", flags), buf));
 	}
 	return 0;
 }
diff --git a/include/haproxy/mux_h2-t.h b/include/haproxy/mux_h2-t.h
index fb2c78cdf..c08592677 100644
--- a/include/haproxy/mux_h2-t.h
+++ b/include/haproxy/mux_h2-t.h
@@ -23,6 +23,7 @@
 #define _HAPROXY_MUX_H2_T_H
 
 #include <haproxy/api-t.h>
+#include <haproxy/show_flags-t.h>
 
 /**** Connection flags (32 bit), in h2c->flags ****/
 
@@ -65,6 +66,29 @@
 #define H2_CF_SHTS_UPDATED      0x00200000  // SETTINGS_HEADER_TABLE_SIZE updated
 #define H2_CF_DTSU_EMITTED      0x00400000  // HPACK Dynamic Table Size Update opcode emitted
 
+/* This function is used to report flags in debugging tools. Please reflect
+ * below any single-bit flag addition above in the same order via the
+ * __APPEND_FLAG macro. The new end of the buffer is returned.
+ */
+static forceinline char *h2c_show_flags(char *buf, size_t len, const char *delim, uint flg)
+{
+#define _(f, ...) __APPEND_FLAG(buf, len, delim, flg, f, #f, __VA_ARGS__)
+	/* prologue */
+	_(0);
+	/* flags */
+	_(H2_CF_MUX_MALLOC, _(H2_CF_MUX_MFULL, _(H2_CF_DEM_DALLOC,
+	_(H2_CF_DEM_DFULL, _(H2_CF_DEM_MBUSY, _(H2_CF_DEM_MROOM,
+	_(H2_CF_DEM_SALLOC, _(H2_CF_DEM_SFULL, _(H2_CF_DEM_TOOMANY,
+	_(H2_CF_DEM_SHORT_READ, _(H2_CF_DEM_IN_PROGRESS, _(H2_CF_GOAWAY_SENT,
+	_(H2_CF_GOAWAY_FAILED, _(H2_CF_WAIT_FOR_HS, _(H2_CF_IS_BACK,
+	_(H2_CF_WINDOW_OPENED, _(H2_CF_RCVD_SHUT, _(H2_CF_END_REACHED,
+	_(H2_CF_RCVD_RFC8441, _(H2_CF_SHTS_UPDATED, _(H2_CF_DTSU_EMITTED)))))))))))))))))))));
+	/* epilogue */
+	_(~0U);
+	return buf;
+#undef _
+}
+
 
 /**** HTTP/2 stream flags (32 bit), in h2s->flags ****/
 
@@ -102,6 +126,29 @@
 #define H2_SF_TUNNEL_ABRT       0x00100000  // A tunnel attempt was aborted
 #define H2_SF_MORE_HTX_DATA     0x00200000  // more data expected from HTX
 
+/* This function is used to report flags in debugging tools. Please reflect
+ * below any single-bit flag addition above in the same order via the
+ * __APPEND_FLAG macro. The new end of the buffer is returned.
+ */
+static forceinline char *h2s_show_flags(char *buf, size_t len, const char *delim, uint flg)
+{
+#define _(f, ...) __APPEND_FLAG(buf, len, delim, flg, f, #f, __VA_ARGS__)
+	/* prologue */
+	_(0);
+	/* flags */
+	_(H2_SF_ES_RCVD, _(H2_SF_ES_SENT, _(H2_SF_RST_RCVD, _(H2_SF_RST_SENT,
+	_(H2_SF_BLK_MBUSY, _(H2_SF_BLK_MROOM, _(H2_SF_BLK_MFCTL,
+	_(H2_SF_BLK_SFCTL, _(H2_SF_DATA_CLEN, _(H2_SF_BODYLESS_RESP,
+	_(H2_SF_BODY_TUNNEL, _(H2_SF_NOTIFIED, _(H2_SF_HEADERS_SENT,
+	_(H2_SF_OUTGOING_DATA, _(H2_SF_HEADERS_RCVD, _(H2_SF_WANT_SHUTR,
+	_(H2_SF_WANT_SHUTW, _(H2_SF_EXT_CONNECT_SENT, _(H2_SF_EXT_CONNECT_RCVD,
+	_(H2_SF_TUNNEL_ABRT, _(H2_SF_MORE_HTX_DATA)))))))))))))))))))));
+	/* epilogue */
+	_(~0U);
+	return buf;
+#undef _
+}
+
 
 /* H2 connection state, in h2c->st0 */
 enum h2_cs {