diff --git a/dev-python/matplotlib/metadata.xml b/dev-python/matplotlib/metadata.xml
index b71983515cc7e..0a91d6a1c64a7 100644
--- a/dev-python/matplotlib/metadata.xml
+++ b/dev-python/matplotlib/metadata.xml
@@ -13,8 +13,8 @@
   </longdescription>
   <use>
     <flag name="excel">Pull <pkg>dev-python/xlwt</pkg> for the exceltools toolkit</flag>
-    <flag name="gtk2">Enable <pkg>x11-libs/gtk-2</pkg> support</flag>
-    <flag name="gtk3">Enable <pkg>x11-libs/gtk-3</pkg> support</flag>
+    <flag name="gtk2">Enable <pkg>x11-libs/gtk+</pkg>:2 support</flag>
+    <flag name="gtk3">Enable <pkg>x11-libs/gtk+</pkg>:3 support</flag>
     <flag name="pyside">Qt support via <pkg>dev-python/pyside</pkg></flag>
   </use>
   <upstream>