diff --git a/jar/plugin.jelly b/jar/plugin.jelly
index b7959186..fdbeedfc 100644
--- a/jar/plugin.jelly
+++ b/jar/plugin.jelly
@@ -53,7 +53,7 @@
         <ant:attribute name="Implementation-Version" value="${pom.currentVersion}"/>
         <ant:attribute name="Implementation-Vendor" value="${pom.organization.name}"/>
         <ant:attribute name="Implementation-Vendor-Id" value="${pom.organization.identifier}"/>
-        <maven:pluginVar var="mainClass" plugin="maven-java-plugin" property="maven.jar.mainclass" />
+        <maven:pluginVar var="mainclass" plugin="maven-java-plugin" property="maven.jar.mainclass" />
         <j:if test="${!empty(mainclass)}">
             <ant:attribute name="Main-Class" value="${mainclass}"/>
         </j:if>