diff --git a/README.md b/README.md
index 530565b..d4a1199 100644
--- a/README.md
+++ b/README.md
@@ -198,6 +198,10 @@ If both `master` and `child` are present, `defeature` will perform a smart merge
 
 `mimosa` will remove features when your run `mimosa watch` or `mimosa build`.
 
+## `build` v `watch` exclusion
+
+A feature called `mimosa-build-exclude` is automatically recognized by mimosa-defeature. This included feature allows for excluding features based on whether Mimosa is running a `watch` or a `build`.  When running a `build`, all code using the `mimosa-build-exclude` feature flag will be removed/commented.
+
 Default Config
 ======
 
diff --git a/src/index.js b/src/index.js
index 267e986..dd67def 100644
--- a/src/index.js
+++ b/src/index.js
@@ -31,6 +31,15 @@ var _prepareFeatures = function(mimosaConfig, options, next) {
   mimosaConfig.defeature.includedFeatures = includedFeatures;
   mimosaConfig.defeature.excludedFeatures = excludedFeatures;
 
+  // when running a build, add feature that
+  // allows defeaturing to be build v watch specific
+  // Allows for leaving things in for dev that need removing for build
+  if (mimosaConfig.isBuild) {
+    excludedFeatures.push("mimosa-build-exclude");
+  } else {
+    includedFeatures.push("mimosa-build-exclude");
+  }
+
   next();
 };