diff --git a/client/src/main/java-mvnd/org/mvndaemon/mvnd/client/DefaultClient.java b/client/src/main/java-mvnd/org/mvndaemon/mvnd/client/DefaultClient.java
index 2f4b1463a..5bd230557 100644
--- a/client/src/main/java-mvnd/org/mvndaemon/mvnd/client/DefaultClient.java
+++ b/client/src/main/java-mvnd/org/mvndaemon/mvnd/client/DefaultClient.java
@@ -132,9 +132,11 @@ public static void main(String[] argv) throws Exception {
         } else {
             dir = parameters.userDir();
         }
+        Path multiModuleProjectDirectory = parameters.multiModuleProjectDirectory(dir);
         System.setProperty(
-                Environment.MAVEN_MULTIMODULE_PROJECT_DIRECTORY.getProperty(),
-                parameters.multiModuleProjectDirectory(dir).toString());
+                Environment.MAVEN_MULTIMODULE_PROJECT_DIRECTORY.getProperty(), multiModuleProjectDirectory.toString());
+        Environment.MAVEN_MULTIMODULE_PROJECT_DIRECTORY.addCommandLineOption(
+                args, multiModuleProjectDirectory.toString());
 
         // .mvn/jvm.config
         if (Files.isRegularFile(parameters.jvmConfigPath())) {
diff --git a/integration-tests/src/test/java/org/mvndaemon/mvnd/it/MavenConfIgnoreExtNativeIT.java b/integration-tests/src/test/java/org/mvndaemon/mvnd/it/MavenConfIgnoreExtNativeIT.java
index 80f6495d8..2e8085795 100644
--- a/integration-tests/src/test/java/org/mvndaemon/mvnd/it/MavenConfIgnoreExtNativeIT.java
+++ b/integration-tests/src/test/java/org/mvndaemon/mvnd/it/MavenConfIgnoreExtNativeIT.java
@@ -26,8 +26,8 @@
 @MvndNativeTest(projectDir = "src/test/projects/maven-conf-ignore-ext")
 class MavenConfIgnoreExtNativeIT extends MavenConfNativeIT {
     @Override
-    protected List<String> mvndParams() {
-        ArrayList<String> result = new ArrayList<>(super.mvndParams());
+    protected List<String> mvndParams(String expression) {
+        ArrayList<String> result = new ArrayList<>(super.mvndParams(expression));
         result.add("-Dmvnd.coreExtensionsExclude=foo:bar");
         return result;
     }
diff --git a/integration-tests/src/test/java/org/mvndaemon/mvnd/it/MavenConfNativeIT.java b/integration-tests/src/test/java/org/mvndaemon/mvnd/it/MavenConfNativeIT.java
index 4a6e5da78..183eca400 100644
--- a/integration-tests/src/test/java/org/mvndaemon/mvnd/it/MavenConfNativeIT.java
+++ b/integration-tests/src/test/java/org/mvndaemon/mvnd/it/MavenConfNativeIT.java
@@ -20,7 +20,6 @@
 
 import javax.inject.Inject;
 
-import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
 
@@ -42,7 +41,7 @@ class MavenConfNativeIT {
     DaemonParameters parameters;
 
     @Test
-    void version() throws IOException, InterruptedException {
+    void version() throws InterruptedException {
         final TestClientOutput o = new TestClientOutput();
         // this test also exercise the "-D foo=bar" syntax for defining properties
         client.execute(o, mvndParams().toArray(new String[0])).assertSuccess();
@@ -51,11 +50,34 @@ void version() throws IOException, InterruptedException {
                 o.getMessages().stream().anyMatch(m -> m.toString().contains(conf)), "Output should contain " + conf);
     }
 
+    @Test
+    void interpolation() throws InterruptedException {
+        final TestClientOutput o = new TestClientOutput();
+        client.execute(o, mvndParams("something").toArray(new String[0])).assertSuccess();
+        String conf = parameters.multiModuleProjectDirectory().toString();
+        assertTrue(
+                o.getMessages().stream().anyMatch(m -> m.toString().contains(conf)), "Output should contain " + conf);
+    }
+
+    @Test
+    void multiModuleProjectDirectory() throws InterruptedException {
+        final TestClientOutput o = new TestClientOutput();
+        client.execute(o, mvndParams("maven.multiModuleProjectDirectory").toArray(new String[0]))
+                .assertSuccess();
+        String conf = parameters.multiModuleProjectDirectory().toString();
+        assertTrue(
+                o.getMessages().stream().anyMatch(m -> m.toString().contains(conf)), "Output should contain " + conf);
+    }
+
     protected List<String> mvndParams() {
+        return mvndParams("maven.conf");
+    }
+
+    protected List<String> mvndParams(String expression) {
         return Arrays.asList(
                 "org.apache.maven.plugins:maven-help-plugin:3.2.0:evaluate",
                 "-D",
-                "expression=maven.conf",
+                "expression=" + expression,
                 "-q",
                 "-DforceStdout",
                 "--raw-streams",