diff --git a/conf/ros-distro/include/ubuntu-bionic/ros-distro-platform-preferred-versions.inc b/conf/ros-distro/include/ubuntu-bionic/ros-distro-platform-preferred-versions.inc
index 45907b6..bb48eef 100644
--- a/conf/ros-distro/include/ubuntu-bionic/ros-distro-platform-preferred-versions.inc
+++ b/conf/ros-distro/include/ubuntu-bionic/ros-distro-platform-preferred-versions.inc
@@ -8,4 +8,5 @@ PREFERRED_VERSION_cppunit ?= "1.14.0"
 PREFERRED_VERSION_linux-raspberrypi ?= "4.4%"
 # Match kernel version of raspberrypi.
 PREFERRED_VERSION_linux-yocto ?= "4.4%"
+PREFERRED_VERSION_python-matplotlib ?= "2.1.1"
 PREFERRED_VERSION_yajl ?= "2.1.0"
diff --git a/conf/ros-distro/include/ubuntu-bionic/ros-distro-platform-recipe-blacklist.inc b/conf/ros-distro/include/ubuntu-bionic/ros-distro-platform-recipe-blacklist.inc
index 2972f25..c7553e0 100644
--- a/conf/ros-distro/include/ubuntu-bionic/ros-distro-platform-recipe-blacklist.inc
+++ b/conf/ros-distro/include/ubuntu-bionic/ros-distro-platform-recipe-blacklist.inc
@@ -4,7 +4,7 @@
 
 # Initially, blacklist any platform duplicates found by "bitbake-layers show-overlayed". Remove from the blacklist once a
 # PREFERRED_VERSION_<PN> setting is made in ros-distro-platform-preferred-versions.inc .
-PNBLACKLIST[python-matplotlib] ?= "Must specify PREFERRED_VERSION"
+# (none)
 
 # Initially, blacklist any platform recipes with multiple versions found by "bitbake-layers show-recipes --multiple" (except for
 # the compilers and runtimes). Remove from the blacklist once a PREFERRED_VERSION_<PN> setting is made in