diff --git a/app/coffee/CompileManager.coffee b/app/coffee/CompileManager.coffee
index dc6c833..dcd1a98 100644
--- a/app/coffee/CompileManager.coffee
+++ b/app/coffee/CompileManager.coffee
@@ -32,8 +32,8 @@ module.exports = CompileManager =
 			injectDraftModeIfRequired (error) ->
 				return callback(error) if error?
 				timer = new Metrics.Timer("run-compile")
-				# find the image tag to log it as a metric
-				tag = request.imageName?.match(/:(.*)/)?[1] or "default"
+				# find the image tag to log it as a metric, e.g. 2015.1 (convert . to - for graphite)
+				tag = request.imageName?.match(/:(.*)/)?[1]?.replace(/\./g,'-') or "default"
 				tag = "other" if project_id?.match(/^[0-9a-f]{24}$/) # exclude smoke test
 				Metrics.inc("compiles")
 				Metrics.inc("compiles-with-image.#{tag}")