diff --git a/dev-ros/rosmsg/files/duplicates.patch b/dev-ros/rosmsg/files/duplicates.patch
new file mode 100644
index 0000000000000..4705f00d2e853
--- /dev/null
+++ b/dev-ros/rosmsg/files/duplicates.patch
@@ -0,0 +1,13 @@
+Index: rosmsg/src/rosmsg/__init__.py
+===================================================================
+--- rosmsg.orig/src/rosmsg/__init__.py
++++ rosmsg/src/rosmsg/__init__.py
+@@ -618,7 +618,7 @@ def rosmsg_cmd_show(mode, full, alias='s
+         if '/' in arg: #package specified
+             rosmsg_debug(rospack, mode, arg, options.raw)
+         else:
+-            found_msgs = list(rosmsg_search(rospack, mode, arg))
++            found_msgs = list(dict.fromkeys(rosmsg_search(rospack, mode, arg)))
+             if not found_msgs:
+                 print("Could not find msg '%s'" % arg, file=sys.stderr)
+                 return 1
diff --git a/dev-ros/rosmsg/rosmsg-1.15.9.ebuild b/dev-ros/rosmsg/rosmsg-1.15.9.ebuild
index ba0d62bb080bb..c750959458b68 100644
--- a/dev-ros/rosmsg/rosmsg-1.15.9.ebuild
+++ b/dev-ros/rosmsg/rosmsg-1.15.9.ebuild
@@ -23,3 +23,9 @@ RDEPEND="
 DEPEND="${RDEPEND}
 	test? ( dev-ros/test_rosmaster[${PYTHON_SINGLE_USEDEP}] )
 "
+PATCHES=( "${FILESDIR}/duplicates.patch" )
+
+src_test() {
+	export ROS_PACKAGE_PATH="${S}/../../:${ROS_PACKAGE_PATH}"
+	ros-catkin_src_test
+}