diff --git a/gradle.properties b/gradle.properties
index 3228c665..0856a9c4 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,5 +1,5 @@
 group = com.gluonhq.attach
-version = 4.0.21-SNAPSHOT
+version = 4.0.21
 
 # disable publish of sha256, sha512
 systemProp.org.gradle.internal.publish.checksums.insecure=true