diff --git a/train-docs/pom.xml b/train-docs/pom.xml
index c6bc1d5..f971c6e 100644
--- a/train-docs/pom.xml
+++ b/train-docs/pom.xml
@@ -17,6 +17,7 @@
 		<upload-docs-zip.phase>deploy</upload-docs-zip.phase>
 
 		<maven.version>3.6.3</maven.version>
+		<maven-gpg-plugin.version>1.6</maven-gpg-plugin.version>
 		<handlebars.version>4.2.0</handlebars.version>
 		<asciidoctorj.version>2.1.0</asciidoctorj.version>
 		<commons-io.version>2.7</commons-io.version>