diff --git a/composer.json b/composer.json
index c3f087ec..410fe78f 100755
--- a/composer.json
+++ b/composer.json
@@ -21,6 +21,9 @@
         "silverstripe/standards": "^1",
         "phpstan/extension-installer": "^1.3"
     },
+    "conflict": {
+        "silverstripe/lumberjack": "4.0.0-alpha1"
+    },
     "extra": {
         "expose": [
             "client/dist",