diff --git a/src/mux_h2.c b/src/mux_h2.c
index 2278a49..d7cf237 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -29,8 +29,9 @@
 #include <eb32tree.h>
 
 
-/* dummy streams returned for closed, refused, idle and states */
+/* dummy streams returned for closed, error, refused, idle and states */
 static const struct h2s *h2_closed_stream;
+static const struct h2s *h2_error_stream;
 static const struct h2s *h2_refused_stream;
 static const struct h2s *h2_idle_stream;
 
@@ -230,6 +231,16 @@
 	.id        = 0,
 };
 
+/* a dmumy closed stream returning a PROTOCOL_ERROR error */
+static const struct h2s *h2_error_stream = &(const struct h2s){
+	.cs        = NULL,
+	.h2c       = NULL,
+	.st        = H2_SS_CLOSED,
+	.errcode   = H2_ERR_PROTOCOL_ERROR,
+	.flags     = 0,
+	.id        = 0,
+};
+
 /* a dmumy closed stream returning a REFUSED_STREAM error */
 static const struct h2s *h2_refused_stream = &(const struct h2s){
 	.cs        = NULL,