diff --git a/tools/volcanoplot/volcanoplot.xml b/tools/volcanoplot/volcanoplot.xml
index 0ec71adc6f4..a51eac966c0 100644
--- a/tools/volcanoplot/volcanoplot.xml
+++ b/tools/volcanoplot/volcanoplot.xml
@@ -321,6 +321,6 @@ A PDF containing a Volcano plot like below. The R code can be output through *Ou
 
     ]]></help>
     <citations>
-        <citation type="doi">doi.org/10.1007/978-3-319-24277-4</citation>
+        <citation type="doi">10.1007/978-3-319-24277-4</citation>
     </citations>
 </tool>