diff --git a/builder/dockerfile.centos_core.build b/builder/dockerfile.centos_core.build
index 06dad21..4574075 100644
--- a/builder/dockerfile.centos_core.build
+++ b/builder/dockerfile.centos_core.build
@@ -22,8 +22,7 @@ RUN cd /tmp/libwebp-1.0.2 && \
 
 RUN useradd -m docker && echo "docker:docker" | chpasswd
 
-COPY . /src
-RUN chown -R docker:docker /src
+COPY --chown=docker:docker . /src/
 
 USER docker
 ENTRYPOINT ["/src/builder/build.sh"]
diff --git a/builder/dockerfile.debian_bullseye.build b/builder/dockerfile.debian_bullseye.build
index 3c19f4c..0a8428e 100644
--- a/builder/dockerfile.debian_bullseye.build
+++ b/builder/dockerfile.debian_bullseye.build
@@ -24,8 +24,7 @@ RUN cd /tmp/libwebp-1.0.2 && \
 
 RUN useradd -m docker && echo "docker:docker" | chpasswd && adduser docker sudo
 
-COPY . /src
-RUN chown -R docker:docker /src
+COPY --chown=docker:docker . /src/
 
 USER docker
 ENTRYPOINT ["/src/builder/build.sh"]
diff --git a/builder/dockerfile.debian_buster.build b/builder/dockerfile.debian_buster.build
index 721b1a6..a47b6fe 100644
--- a/builder/dockerfile.debian_buster.build
+++ b/builder/dockerfile.debian_buster.build
@@ -24,8 +24,7 @@ RUN cd /tmp/libwebp-1.0.2 && \
 
 RUN useradd -m docker && echo "docker:docker" | chpasswd && adduser docker sudo
 
-COPY . /src
-RUN chown -R docker:docker /src
+COPY --chown=docker:docker . /src/
 
 USER docker
 ENTRYPOINT ["/src/builder/build.sh"]
diff --git a/builder/dockerfile.fedora_thirtythree.build b/builder/dockerfile.fedora_thirtythree.build
index be70715..8dc4b29 100644
--- a/builder/dockerfile.fedora_thirtythree.build
+++ b/builder/dockerfile.fedora_thirtythree.build
@@ -31,8 +31,7 @@ RUN cd /tmp/libwebp-1.0.2 && \
 
 RUN useradd -m docker && echo "docker:docker" | chpasswd
 
-COPY . /src
-RUN chown -R docker:docker /src
+COPY --chown=docker:docker . /src/
 
 USER docker
 ENTRYPOINT ["/src/builder/build.sh"]
diff --git a/builder/dockerfile.kali_kali-rolling.build b/builder/dockerfile.kali_kali-rolling.build
index 6087895..9705e42 100644
--- a/builder/dockerfile.kali_kali-rolling.build
+++ b/builder/dockerfile.kali_kali-rolling.build
@@ -24,8 +24,7 @@ RUN cd /tmp/libwebp-1.0.2 && \
 
 RUN useradd -m docker && echo "docker:docker" | chpasswd && adduser docker sudo
 
-COPY . /src
-RUN chown -R docker:docker /src
+COPY --chown=docker:docker . /src/
 
 USER docker
 ENTRYPOINT ["/src/builder/build.sh"]
diff --git a/builder/dockerfile.ubuntu1604.build b/builder/dockerfile.ubuntu1604.build
index a938ff8..8ca3260 100644
--- a/builder/dockerfile.ubuntu1604.build
+++ b/builder/dockerfile.ubuntu1604.build
@@ -14,8 +14,7 @@ RUN cd /tmp/libwebp-1.0.2 && ./configure && make && make install
 
 RUN useradd -m docker && echo "docker:docker" | chpasswd && adduser docker sudo
 
-COPY . /src
-RUN chown -R docker:docker /src
+COPY --chown=docker:docker . /src/
 
 
 USER docker
diff --git a/builder/dockerfile.ubuntu_bionic.build b/builder/dockerfile.ubuntu_bionic.build
index cee01e1..d95bd02 100644
--- a/builder/dockerfile.ubuntu_bionic.build
+++ b/builder/dockerfile.ubuntu_bionic.build
@@ -28,8 +28,7 @@ RUN cd /tmp/libwebp-1.0.2 && \
 
 RUN useradd -m docker && echo "docker:docker" | chpasswd && adduser docker sudo
 
-COPY . /src
-RUN chown -R docker:docker /src
+COPY --chown=docker:docker . /src/
 
 USER docker
 ENTRYPOINT ["/src/builder/build.sh"]
diff --git a/builder/dockerfile.ubuntu_focal.build b/builder/dockerfile.ubuntu_focal.build
index 9c52a77..d0562d1 100644
--- a/builder/dockerfile.ubuntu_focal.build
+++ b/builder/dockerfile.ubuntu_focal.build
@@ -24,8 +24,7 @@ RUN cd /tmp/libwebp-1.0.2 && \
 
 RUN useradd -m docker && echo "docker:docker" | chpasswd && adduser docker sudo
 
-COPY . /src
-RUN chown -R docker:docker /src
+COPY --chown=docker:docker . /src/
 
 USER docker
 ENTRYPOINT ["/src/builder/build.sh"]
diff --git a/common/network/websocket.c b/common/network/websocket.c
index 3d3111d..47ac11d 100644
--- a/common/network/websocket.c
+++ b/common/network/websocket.c
@@ -583,7 +583,7 @@ int parse_handshake(ws_ctx_t *ws_ctx, char *handshake) {
     headers->host[end-start] = '\0';
 
     headers->origin[0] = '\0';
-    start = strstr(handshake, "\r\nOrigin: ");
+    start = strcasestr(handshake, "\r\nOrigin: ");
     if (start) {
         start += 10;
     } else {
diff --git a/common/rfb/VNCServerST.cxx b/common/rfb/VNCServerST.cxx
index fd13cf3..a564021 100644
--- a/common/rfb/VNCServerST.cxx
+++ b/common/rfb/VNCServerST.cxx
@@ -273,6 +273,11 @@ void VNCServerST::removeSocket(network::Socket* sock) {
   std::list<VNCSConnectionST*>::iterator ci;
   for (ci = clients.begin(); ci != clients.end(); ci++) {
     if ((*ci)->getSock() == sock) {
+
+      if (clipboardClient == *ci)
+        handleClipboardAnnounce(*ci, false);
+      clipboardRequestors.remove(*ci);
+
       // - Delete the per-Socket resources
       delete *ci;