diff --git a/build.gradle b/build.gradle
index fbabcc1..d347609 100644
--- a/build.gradle
+++ b/build.gradle
@@ -68,7 +68,12 @@ version = System.getenv('RELEASE_VERSION') ?: release.projectVersion
 description = '''
 Support for additional non-standard iCalendar objects
 '''
-ext.isReleaseVersion = !version.endsWith("SNAPSHOT")
+ext {
+    isReleaseVersion = !version.endsWith("SNAPSHOT")
+    // sonatype credentials
+    sonatypeUsername = project.hasProperty('sonatypeUsername') ? project.getProperty('sonatypeUsername') : ''
+    sonatypePassword = project.hasProperty('sonatypePassword') ? project.getProperty('sonatypePassword') : ''
+}
 
 uploadArchives {
     repositories {