diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/.gitignore b/src/sbt-test/sbteclipse/08-jdt-settings/.gitignore
new file mode 100644
index 0000000..5fcbd56
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/.gitignore
@@ -0,0 +1 @@
+!.settings
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/b/expected b/src/sbt-test/sbteclipse/08-jdt-settings/b/expected
new file mode 100644
index 0000000..f736ce2
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/b/expected
@@ -0,0 +1,3 @@
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.source=1.8
+org.eclipse.jdt.core.compiler.compliance=1.8
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/build.sbt b/src/sbt-test/sbteclipse/08-jdt-settings/build.sbt
new file mode 100644
index 0000000..77bcea7
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/build.sbt
@@ -0,0 +1,92 @@
+
+val check = TaskKey[Unit]("check") := {
+  import java.util.Properties
+  import java.io.FileInputStream
+  import scala.collection.JavaConverters._
+
+  val s: TaskStreams = streams.value
+  val expectedFile = baseDirectory.value / "expected"
+  val resultFile = baseDirectory.value / ".settings" / "org.eclipse.jdt.core.prefs"
+
+  if (expectedFile.exists()) {
+    val expectedIn = new FileInputStream(expectedFile)
+    val expected =
+      try {
+        val prop = new Properties()
+        prop.load(expectedIn)
+        prop.asScala.toMap
+      } finally {
+        expectedIn.close()
+      }
+
+    val resultIn = new FileInputStream(resultFile)
+    val result =
+      try {
+        val prop = new Properties()
+        prop.load(resultIn)
+        prop.asScala.toMap
+      } finally {
+        resultIn.close()
+      }
+
+    if (expected == result)
+      s.log.info(s"correct data: ${resultFile}")
+    else
+      sys.error("Expected settings to be '%s', but was '%s'!".format(expected, result))
+  }
+}
+
+// ensure org.eclipse.core.resources.prefs will always be generated
+ThisBuild / scalacOptions ++= Seq("-encoding", "utf-8")
+
+// check that no JDT file is generated (default ignore, no runtime defined)
+lazy val projectA = (project in file("a"))
+  .settings(
+    check
+  )
+
+// check that a new and correct JDT file is generated
+lazy val projectB = (project in file("b"))
+  .settings(
+    EclipseKeys.executionEnvironment := Some(EclipseExecutionEnvironment.JavaSE18),
+    EclipseKeys.jdtMode := EclipseJDTMode.Update,
+    check
+  )
+
+// check that a correct JDT file is is not updated
+lazy val projectC = (project in file("c"))
+  .settings(
+    EclipseKeys.executionEnvironment := Some(EclipseExecutionEnvironment.JavaSE11),
+    EclipseKeys.jdtMode := EclipseJDTMode.Update,
+    check
+  )
+
+// check that an outdated JDT file is selectively updated
+lazy val projectD = (project in file("d"))
+  .settings(
+    EclipseKeys.executionEnvironment := Some(EclipseExecutionEnvironment.JavaSE_17),
+    EclipseKeys.jdtMode := EclipseJDTMode.Update,
+    check
+  )
+
+// check that a JDT file is overwritten
+lazy val projectE = (project in file("e"))
+  .settings(
+    EclipseKeys.executionEnvironment := Some(EclipseExecutionEnvironment.JavaSE11),
+    EclipseKeys.jdtMode := EclipseJDTMode.Overwrite,
+    check
+  )
+
+// check that an JDT file is removed
+lazy val projectF = (project in file("f"))
+  .settings(
+    EclipseKeys.jdtMode := EclipseJDTMode.Remove,
+    check
+  )
+
+// check that an JDT file is default ignored, but written on command
+lazy val projectG = (project in file("g"))
+  .settings(
+    EclipseKeys.executionEnvironment := Some(EclipseExecutionEnvironment.JavaSE18),
+    check
+  )
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/c/.settings/org.eclipse.jdt.core.prefs b/src/sbt-test/sbteclipse/08-jdt-settings/c/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..7fc5c6f
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/c/.settings/org.eclipse.jdt.core.prefs
@@ -0,0 +1,4 @@
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
+org.eclipse.jdt.core.compiler.source=11
+org.eclipse.jdt.core.compiler.compliance=11
+dummy.key=abc
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/c/expected b/src/sbt-test/sbteclipse/08-jdt-settings/c/expected
new file mode 100644
index 0000000..7fc5c6f
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/c/expected
@@ -0,0 +1,4 @@
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
+org.eclipse.jdt.core.compiler.source=11
+org.eclipse.jdt.core.compiler.compliance=11
+dummy.key=abc
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/d/.settings/org.eclipse.jdt.core.prefs b/src/sbt-test/sbteclipse/08-jdt-settings/d/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..7fc5c6f
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/d/.settings/org.eclipse.jdt.core.prefs
@@ -0,0 +1,4 @@
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
+org.eclipse.jdt.core.compiler.source=11
+org.eclipse.jdt.core.compiler.compliance=11
+dummy.key=abc
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/d/expected b/src/sbt-test/sbteclipse/08-jdt-settings/d/expected
new file mode 100644
index 0000000..23a0c69
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/d/expected
@@ -0,0 +1,4 @@
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=17
+org.eclipse.jdt.core.compiler.source=17
+org.eclipse.jdt.core.compiler.compliance=17
+dummy.key=abc
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/e/.settings/org.eclipse.jdt.core.prefs b/src/sbt-test/sbteclipse/08-jdt-settings/e/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..7fc5c6f
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/e/.settings/org.eclipse.jdt.core.prefs
@@ -0,0 +1,4 @@
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
+org.eclipse.jdt.core.compiler.source=11
+org.eclipse.jdt.core.compiler.compliance=11
+dummy.key=abc
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/e/expected b/src/sbt-test/sbteclipse/08-jdt-settings/e/expected
new file mode 100644
index 0000000..3bc34e2
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/e/expected
@@ -0,0 +1,3 @@
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
+org.eclipse.jdt.core.compiler.source=11
+org.eclipse.jdt.core.compiler.compliance=11
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/f/.settings/org.eclipse.jdt.core.prefs b/src/sbt-test/sbteclipse/08-jdt-settings/f/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..7fc5c6f
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/f/.settings/org.eclipse.jdt.core.prefs
@@ -0,0 +1,4 @@
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
+org.eclipse.jdt.core.compiler.source=11
+org.eclipse.jdt.core.compiler.compliance=11
+dummy.key=abc
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/g/.settings/org.eclipse.jdt.core.prefs b/src/sbt-test/sbteclipse/08-jdt-settings/g/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..ccb0942
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/g/.settings/org.eclipse.jdt.core.prefs
@@ -0,0 +1 @@
+dummy.key=abc
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/g/expected b/src/sbt-test/sbteclipse/08-jdt-settings/g/expected
new file mode 100644
index 0000000..ccb0942
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/g/expected
@@ -0,0 +1 @@
+dummy.key=abc
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/project/plugins.sbt b/src/sbt-test/sbteclipse/08-jdt-settings/project/plugins.sbt
new file mode 100644
index 0000000..542d181
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/project/plugins.sbt
@@ -0,0 +1,7 @@
+{
+  val pluginVersion = System.getProperty("plugin.version")
+  if(pluginVersion == null)
+    throw new RuntimeException("""|The system property 'plugin.version' is not defined.
+                                  |Specify this property using the scriptedLaunchOpts -D.""".stripMargin)
+  else addSbtPlugin("com.github.sbt" % "sbt-eclipse" % pluginVersion)
+}
diff --git a/src/sbt-test/sbteclipse/08-jdt-settings/test b/src/sbt-test/sbteclipse/08-jdt-settings/test
new file mode 100644
index 0000000..2e764ee
--- /dev/null
+++ b/src/sbt-test/sbteclipse/08-jdt-settings/test
@@ -0,0 +1,62 @@
+# timestamp marker file 
+$ touch marker
+
+$ exists f/.settings/org.eclipse.jdt.core.prefs
+
+> eclipse
+
+> check
+
+$ exists a/.settings/org.eclipse.core.resources.prefs
+-$ exists a/.settings/org.eclipse.jdt.core.prefs
+
+$ exists b/.settings/org.eclipse.jdt.core.prefs
+$ newer b/.settings/org.eclipse.jdt.core.prefs marker
+
+$ exists c/.settings/org.eclipse.jdt.core.prefs
+$ newer marker c/.settings/org.eclipse.jdt.core.prefs
+
+$ exists d/.settings/org.eclipse.jdt.core.prefs
+$ newer d/.settings/org.eclipse.jdt.core.prefs marker
+
+$ exists e/.settings/org.eclipse.jdt.core.prefs
+$ newer e/.settings/org.eclipse.jdt.core.prefs marker
+
+$ exists f/.settings/org.eclipse.core.resources.prefs
+-$ exists f/.settings/org.eclipse.jdt.core.prefs
+
+$ exists g/.settings/org.eclipse.jdt.core.prefs
+$ newer marker g/.settings/org.eclipse.jdt.core.prefs
+
+# test overwrite mode via command arg
+$ touch marker
+> eclipse jdt-mode=Overwrite
+# no runtime defined for a
+-$ exists a/.settings/org.eclipse.jdt.core.prefs
+$ newer b/.settings/org.eclipse.jdt.core.prefs marker
+$ newer c/.settings/org.eclipse.jdt.core.prefs marker
+$ newer d/.settings/org.eclipse.jdt.core.prefs marker
+$ newer e/.settings/org.eclipse.jdt.core.prefs marker
+-$ exists f/.settings/org.eclipse.jdt.core.prefs
+$ newer g/.settings/org.eclipse.jdt.core.prefs marker
+
+# test ignore mode via command arg
+$ touch marker
+> eclipse jdt-mode=Ignore
+-$ exists a/.settings/org.eclipse.jdt.core.prefs
+$ newer marker b/.settings/org.eclipse.jdt.core.prefs
+$ newer marker c/.settings/org.eclipse.jdt.core.prefs
+$ newer marker d/.settings/org.eclipse.jdt.core.prefs
+$ newer marker e/.settings/org.eclipse.jdt.core.prefs
+-$ exists f/.settings/org.eclipse.jdt.core.prefs
+$ newer marker g/.settings/org.eclipse.jdt.core.prefs
+
+# test remove mode via command arg
+> eclipse jdt-mode=Remove
+-$ exists a/.settings/org.eclipse.jdt.core.prefs
+-$ exists b/.settings/org.eclipse.jdt.core.prefs
+-$ exists c/.settings/org.eclipse.jdt.core.prefs
+-$ exists d/.settings/org.eclipse.jdt.core.prefs
+-$ exists e/.settings/org.eclipse.jdt.core.prefs
+-$ exists f/.settings/org.eclipse.jdt.core.prefs
+-$ exists g/.settings/org.eclipse.jdt.core.prefs