diff --git a/tools/psy-maps/psy-maps.xml b/tools/psy-maps/psy-maps.xml
index da9fdba..1e19bf5 100644
--- a/tools/psy-maps/psy-maps.xml
+++ b/tools/psy-maps/psy-maps.xml
@@ -1,4 +1,4 @@
-<tool id="psy_maps" name="map plot" version="1.3.0" profile="23.0">
+<tool id="psy_maps" name="map plot" version="1.3.1" profile="23.0">
     <description>gridded (lat/lon) netCDF data</description>
     <edam_topics>
       <edam_topic>topic_3855</edam_topic>
@@ -9,6 +9,7 @@
     </edam_operations>
     <requirements>
         <requirement type="package" version="3">python</requirement>
+        <requirement type="package" version="3.9.2">matplotlib</requirement>
         <requirement type="package" version="1.4.3">psyplot</requirement>
         <requirement type="package" version="1.4.2">psy-maps</requirement>
         <requirement type="package" version="1.4.0">psy-reg</requirement>