diff --git a/BauSystem_19/build.gradle b/BauSystem_19/build.gradle
index 7973f1b0..900fce9d 100644
--- a/BauSystem_19/build.gradle
+++ b/BauSystem_19/build.gradle
@@ -28,7 +28,7 @@ version '1.0'
 compileJava.options.encoding = 'UTF-8'
 
 sourceCompatibility = 17
-targetCompatibility = 17
+targetCompatibility = 11
 
 sourceSets {
     main {
diff --git a/BauSystem_20/build.gradle b/BauSystem_20/build.gradle
index 17121b8d..b2620127 100644
--- a/BauSystem_20/build.gradle
+++ b/BauSystem_20/build.gradle
@@ -28,7 +28,7 @@ version '1.0'
 compileJava.options.encoding = 'UTF-8'
 
 sourceCompatibility = 17
-targetCompatibility = 17
+targetCompatibility = 11
 
 sourceSets {
     main {