diff --git a/2.3/Dockerfile b/2.3/Dockerfile
index 82096aea7..e9fc71de2 100644
--- a/2.3/Dockerfile
+++ b/2.3/Dockerfile
@@ -54,7 +54,7 @@ RUN set -ex \
 	\
 	&& gem update --system "$RUBYGEMS_VERSION"
 
-ENV BUNDLER_VERSION 1.13.5
+ENV BUNDLER_VERSION 1.13.6
 
 RUN gem install bundler --version "$BUNDLER_VERSION"
 
diff --git a/2.3/alpine/Dockerfile b/2.3/alpine/Dockerfile
index 28ba9ed6b..1dd3031fc 100644
--- a/2.3/alpine/Dockerfile
+++ b/2.3/alpine/Dockerfile
@@ -89,7 +89,7 @@ RUN set -ex \
 	\
 	&& gem update --system "$RUBYGEMS_VERSION"
 
-ENV BUNDLER_VERSION 1.13.5
+ENV BUNDLER_VERSION 1.13.6
 
 RUN gem install bundler --version "$BUNDLER_VERSION"
 
diff --git a/2.3/slim/Dockerfile b/2.3/slim/Dockerfile
index 0a6458149..5ba05b686 100644
--- a/2.3/slim/Dockerfile
+++ b/2.3/slim/Dockerfile
@@ -76,7 +76,7 @@ RUN set -ex \
 	\
 	&& gem update --system "$RUBYGEMS_VERSION"
 
-ENV BUNDLER_VERSION 1.13.5
+ENV BUNDLER_VERSION 1.13.6
 
 RUN gem install bundler --version "$BUNDLER_VERSION"