diff --git a/server/build.gradle b/server/build.gradle
index 00c3d42..dc1ed71 100644
--- a/server/build.gradle
+++ b/server/build.gradle
@@ -6,10 +6,10 @@ buildscript {
 }
 
 ext.versions = [
-	xtext: '2.13.0-SNAPSHOT',
+    xtext: '2.13.0-SNAPSHOT',
     elk: '0.3.0-SNAPSHOT',
-	sprotty: '0.2.0-SNAPSHOT',
-	lsp4j: '0.3.0-SNAPSHOT',
+    sprotty: '0.2.0-SNAPSHOT',
+    lsp4j: '0.2.1',
     jetty: '9.4.2.v20170220',
     slf4j: '1.7.24'
 ]