diff --git a/jdiff/plugin.jelly b/jdiff/plugin.jelly
index 4aae425c..1c3dc969 100644
--- a/jdiff/plugin.jelly
+++ b/jdiff/plugin.jelly
@@ -28,7 +28,7 @@
   <j:if test="${bootstrapping == null}">
     <!-- Poor mans version check - plugin dependencies still suck for multiple versions -->
     <maven:get plugin="maven-scm-plugin" property="plugin" var="scmPlugin" />
-    <j:if test="${scmPlugin.currentVersion.compareTo('1.5') lt 0}">
+    <j:if test="${empty(scmPlugin) or scmPlugin.currentVersion.compareTo('1.5') lt 0}">
       <ant:fail>
         Must have SCM plugin v1.5 installed to use this version of the jdiff plugin.
         Try: maven plugin:download -DgroupId=maven -DartifactId=maven-scm-plugin -Dversion=1.5