diff --git a/.idea/kotlinc.xml b/.idea/kotlinc.xml
index 693265dae..8fa75fe1c 100644
--- a/.idea/kotlinc.xml
+++ b/.idea/kotlinc.xml
@@ -1,13 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="Kotlin2JvmCompilerArguments">
-    <option name="jvmTarget" value="17" />
-  </component>
-  <component name="KotlinCommonCompilerArguments">
-    <option name="apiVersion" value="1.9" />
-    <option name="languageVersion" value="1.9" />
+    <option name="jvmTarget" value="11" />
   </component>
   <component name="KotlinJpsPluginSettings">
-    <option name="version" value="1.9.24" />
+    <option name="version" value="1.9.20" />
   </component>
 </project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index e24ec7891..209ccd3b7 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -22,7 +22,7 @@
   <component name="FrameworkDetectionExcludesConfiguration">
     <type id="Python" />
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="openjdk-17" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="openjdk-11" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/docs/source/compiling.rst b/docs/source/compiling.rst
index 1c769d422..8e8c86eb7 100644
--- a/docs/source/compiling.rst
+++ b/docs/source/compiling.rst
@@ -62,7 +62,7 @@ For normal use, the ``installDist`` task should suffice and after succesful comp
 
 .. hint::
     Development and testing is done on Linux using the IntelliJ IDEA IDE,
-    but the actual prog8 compiler should run on all operating systems that provide a java runtime (version 17 or newer).
+    but the actual prog8 compiler should run on all operating systems that provide a java runtime (version 11 or newer).
     If you do have trouble building or running the compiler on your operating system, please let me know!
 
     To successfully build and debug in IDEA, you have to manually generate the Antlr-parser classes first.
@@ -325,7 +325,7 @@ Troubleshooting
 
 Compiler doesn't run, complains about "UnsupportedClassVersionError"
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-You need to install and use JDK version 17 or newer to run the prog8 compiler. Check this with "java -version".
+You need to install and use JDK version 11 or newer to run the prog8 compiler. Check this with "java -version".
 See :ref:`requirements`.
 
 The computer just resets (at the end of the program)
diff --git a/docs/source/index.rst b/docs/source/index.rst
index 0d84b3713..5b234bbf8 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -193,9 +193,9 @@ It's easy to compile yourself, but a recent precompiled .exe (only for Windows)
 *You need at least version 1.58.0 of this assembler.*
 If you are on Linux, there's probably a "64tass" package in the repositories, but check if it is a recent enough version.
 
-A **Java runtime (jre or jdk), version 17 or newer**  is required to run the prog8 compiler itself.
+A **Java runtime (jre or jdk), version 11 or newer**  is required to run the prog8 compiler itself.
 If you're scared of Oracle's licensing terms, get one of the versions of another vendor. Even Microsoft provides their own version.
-Other OpenJDK builds can be found at `Adoptium <https://adoptium.net/temurin/releases/?version=17>`_ .
+Other OpenJDK builds can be found at `Adoptium <https://adoptium.net/temurin/releases/?version=11>`_ .
 For MacOS you can also use the Homebrew system to install a recent version of OpenJDK.
 
 Finally: an **emulator** (or a real machine of course) to test and run your programs on.
diff --git a/gradle.properties b/gradle.properties
index 2a71eb14b..2749eda69 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -3,6 +3,6 @@ org.gradle.console=rich
 org.gradle.parallel=true
 org.gradle.daemon=true
 kotlin.code.style=official
-javaVersion=17
+javaVersion=11
 kotlinVersion=1.9.24
 version=10.3.1-SNAPSHOT