diff --git a/src/main.cr b/src/main.cr
index 4b4692f..e0f51a5 100644
--- a/src/main.cr
+++ b/src/main.cr
@@ -261,7 +261,7 @@ class Service
 		ENV["SERVICE_ENVIRONMENT_TYPE"] = @environment.type.to_s
 	end
 	private def evaluate(string)
-		string.sub /%{[a-zA-Z]+}/ do |match|
+		string.gsub /%{[a-zA-Z]+}/ do |match|
 			match = match[2..match.size-2]
 
 			if match.downcase == "environment"