diff --git a/manager/src/main/java/io/aklivity/zilla/manager/internal/commands/install/ZpmInstall.java b/manager/src/main/java/io/aklivity/zilla/manager/internal/commands/install/ZpmInstall.java
index 9278bfc1d7..5b3f2ca336 100644
--- a/manager/src/main/java/io/aklivity/zilla/manager/internal/commands/install/ZpmInstall.java
+++ b/manager/src/main/java/io/aklivity/zilla/manager/internal/commands/install/ZpmInstall.java
@@ -704,7 +704,9 @@ private void generateLauncher() throws IOException
         Path zillaPath = launcherDir.resolve("zilla");
         Files.write(zillaPath, Arrays.asList(
                 "#!/bin/sh",
-                "JAVA_OPTIONS+=\"${ZILLA_INCUBATOR_ENABLED:+ -Dzilla.incubator.enabled=$ZILLA_INCUBATOR_ENABLED}\"",
+                "if [ -n \"$ZILLA_INCUBATOR_ENABLED\" ]; then",
+                "JAVA_OPTIONS=\"$JAVA_OPTIONS -Dzilla.incubator.enabled=$ZILLA_INCUBATOR_ENABLED\"",
+                "fi",
                 "cd \"${0%/*}\"",
                 String.format(String.join(" ", Arrays.asList(
                     "exec %s/bin/java",