diff --git a/landingzones/caf_launchpad/variables.tf b/landingzones/caf_launchpad/variables.tf
index c6b4a5c581..acf69cd2f9 100644
--- a/landingzones/caf_launchpad/variables.tf
+++ b/landingzones/caf_launchpad/variables.tf
@@ -47,7 +47,7 @@ variable enable {
 }
 
 variable prefix {
-  default = ""
+  default = null
 }
 
 variable use_slug {
@@ -188,4 +188,4 @@ variable azurerm_routes {
 
 variable keyvault_access_policies_azuread_apps {
   default = {}
-}
\ No newline at end of file
+}