diff --git a/src/get-port.cr b/src/get-port.cr
index 4428fb7..9757484 100644
--- a/src/get-port.cr
+++ b/src/get-port.cr
@@ -7,7 +7,7 @@ PORTS_CACHE_DIRECTORY = "#{CACHE_DIRECTORY}/ports/"
 service = ARGV[0]
 wanted_default_port = ARGV[1]?.try &.to_i
 
-service_port_file = "#{PORTS_CACHE_DIRECTORY}/#{service}"
+service_port_file = "#{PORTS_CACHE_DIRECTORY}/#{service.gsub /\//, ":"}"
 
 begin
 	if File.exists? service_port_file