diff --git a/.dockerignore b/.dockerignore
index 78ae78ea..538648ad 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -2,3 +2,4 @@ build
 CMakeCache.txt
 ws/CMakeCache.txt
 test/build
+makefile
diff --git a/docker/Dockerfile.alpine b/docker/Dockerfile.alpine
index 0df5d453..e42528f0 100644
--- a/docker/Dockerfile.alpine
+++ b/docker/Dockerfile.alpine
@@ -15,7 +15,7 @@ COPY --chown=app:app . /opt
 WORKDIR /opt
 
 USER app
-RUN make ws_mbedtls_install && \
+RUN make -f makefile.dev ws_mbedtls_install && \
     sh tools/trim_repo_for_docker.sh
 
 FROM alpine:3.12 as runtime
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 171bcf6c..8403622b 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 All changes to this project will be documented in this file.
 
+## [11.0.6] - 2020-12-22
+
+(build) rename makefile to makefile.dev to ease cmake BuildExternal (fix #261)
+
 ## [11.0.5] - 2020-12-17
 
 (ws) Implement simple header based websocket authorization technique to reject
diff --git a/ixwebsocket/IXWebSocketVersion.h b/ixwebsocket/IXWebSocketVersion.h
index 30bff6e1..739fcced 100644
--- a/ixwebsocket/IXWebSocketVersion.h
+++ b/ixwebsocket/IXWebSocketVersion.h
@@ -6,4 +6,4 @@
 
 #pragma once
 
-#define IX_WEBSOCKET_VERSION "11.0.5"
+#define IX_WEBSOCKET_VERSION "11.0.6"
diff --git a/makefile b/makefile.dev
similarity index 100%
rename from makefile
rename to makefile.dev