diff --git a/root/etc/cont-init.d/30-config b/root/etc/cont-init.d/30-config
index 2a2368f..d83d0f4 100644
--- a/root/etc/cont-init.d/30-config
+++ b/root/etc/cont-init.d/30-config
@@ -4,7 +4,7 @@
 PHP_MEMORY_LIMIT=${PHP_MEMORY_LIMIT:-512M}
 MAX_UPLOAD=${MAX_UPLOAD:-5000}
 PHP_MAX_FILE_UPLOAD=${PHP_MAX_FILE_UPLOAD:-200}
-USABLE_MAX_UPLOAD="${MAX_UPLOAD//[!0-9]/}"
+USABLE_MAX_UPLOAD=${MAX_UPLOAD//[!0-9]/}
 
 # create our folders
 mkdir -p \