diff --git a/build.gradle b/build.gradle
index 744734427e6829602304074b04b4c4d44620dbb1..e0f8fe658175891263decf16d973200787b84e13 100644
--- a/build.gradle
+++ b/build.gradle
@@ -31,7 +31,7 @@ project(':de.prob.core') {
 	}
 
 
-        def parser_version = '2.5.4'
+        def parser_version = '2.5.1'
 
 	dependencies {
 	 compile group: "de.hhu.stups", name: "answerparser", version: parser_version , changing: true
diff --git a/de.prob.core/build.gradle b/de.prob.core/build.gradle
index c444785c8ec6f71906c250749522045d323fab77..acb95c76d5d0a7ee5e64af9b63a73db65109d4fd 100644
--- a/de.prob.core/build.gradle
+++ b/de.prob.core/build.gradle
@@ -1,6 +1,6 @@
 apply plugin: 'java'
 
-def parser_version = '2.5.4'
+def parser_version = '2.5.1'
 
 dependencies {
  compile group: "de.hhu.stups", name: "answerparser", version: parser_version , changing: true