add Piotr P. Karwasz
diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 708f503..6b29f06 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -353,6 +353,7 @@
 Phillip Wells
 Pierre Delisle
 Pierre Dittgen
+Piotr P. Karwasz
 Preston Bannister
 Ralf Hergert
 Rami Ojares
diff --git a/contributors.xml b/contributors.xml
index ddc55ec..6b25301 100644
--- a/contributors.xml
+++ b/contributors.xml
@@ -1461,6 +1461,10 @@
     <last>Dittgen</last>
   </name>
   <name>
+    <first>Piotr</first>
+    <middle>P.</middle>
+    <last>Karwasz</last>
+  <name>
     <first>Preston</first>
     <last>Bannister</last>
   </name>