diff --git a/core/src/protocols_handler/mod.rs b/core/src/protocols_handler/mod.rs
index 952dd4c2..4151d040 100644
--- a/core/src/protocols_handler/mod.rs
+++ b/core/src/protocols_handler/mod.rs
@@ -295,8 +295,6 @@ pub enum ProtocolsHandlerUpgrErr<TUpgrErr> {
     Timeout,
     /// There was an error in the timer used.
     Timer,
-    /// The remote muxer denied the attempt to open a substream.
-    MuxerDeniedSubstream,
     /// Error while upgrading the substream to the protocol we want.
     Upgrade(UpgradeError<TUpgrErr>),
 }
@@ -313,9 +311,6 @@ where
             ProtocolsHandlerUpgrErr::Timer => {
                 write!(f, "Timer error while opening a substream")
             },
-            ProtocolsHandlerUpgrErr::MuxerDeniedSubstream => {
-                write!(f, "Remote muxer denied our attempt to open a substream")
-            },
             ProtocolsHandlerUpgrErr::Upgrade(err) => write!(f, "{}", err),
         }
     }
@@ -329,7 +324,6 @@ where
         match self {
             ProtocolsHandlerUpgrErr::Timeout => None,
             ProtocolsHandlerUpgrErr::Timer => None,
-            ProtocolsHandlerUpgrErr::MuxerDeniedSubstream => None,
             ProtocolsHandlerUpgrErr::Upgrade(err) => Some(err),
         }
     }
diff --git a/core/src/protocols_handler/select.rs b/core/src/protocols_handler/select.rs
index 4e62afa4..2ffcc2a0 100644
--- a/core/src/protocols_handler/select.rs
+++ b/core/src/protocols_handler/select.rs
@@ -162,9 +162,6 @@ where
     #[inline]
     fn inject_dial_upgrade_error(&mut self, info: Self::OutboundOpenInfo, error: ProtocolsHandlerUpgrErr<<Self::OutboundProtocol as OutboundUpgrade<Self::Substream>>::Error>) {
         match (info, error) {
-            (EitherOutput::First(info), ProtocolsHandlerUpgrErr::MuxerDeniedSubstream) => {
-                self.proto1.inject_dial_upgrade_error(info, ProtocolsHandlerUpgrErr::MuxerDeniedSubstream)
-            },
             (EitherOutput::First(info), ProtocolsHandlerUpgrErr::Timer) => {
                 self.proto1.inject_dial_upgrade_error(info, ProtocolsHandlerUpgrErr::Timer)
             },
@@ -180,9 +177,6 @@ where
             (EitherOutput::First(_), ProtocolsHandlerUpgrErr::Upgrade(UpgradeError::Apply(EitherError::B(_)))) => {
                 panic!("Wrong API usage; the upgrade error doesn't match the outbound open info");
             },
-            (EitherOutput::Second(info), ProtocolsHandlerUpgrErr::MuxerDeniedSubstream) => {
-                self.proto2.inject_dial_upgrade_error(info, ProtocolsHandlerUpgrErr::MuxerDeniedSubstream)
-            },
             (EitherOutput::Second(info), ProtocolsHandlerUpgrErr::Timeout) => {
                 self.proto2.inject_dial_upgrade_error(info, ProtocolsHandlerUpgrErr::Timeout)
             },