diff --git a/build_jael/README.md b/build_jael/README.md
index 6a22c948..86b551eb 100644
--- a/build_jael/README.md
+++ b/build_jael/README.md
@@ -40,5 +40,10 @@ targets:
 Pass `minify: true` in the build configuration to produce "minified" HTML,
 without newlines or whitespace (other than where it is required).
 
+## Strict Variable Resolution
+By default, identifiers pointing to non-existent symbols return `null`.
+To disable this and throw an error when an undefined symbol is referenced,
+set `strict: true` in `build.yaml`.
+
 To apply additional transforms to parsed documents, provide a
 set of `patch` functions, like in `package:jael_preprocessor`.
\ No newline at end of file
diff --git a/jael.iml b/jael.iml
index 6f2c9ef7..a6e113de 100644
--- a/jael.iml
+++ b/jael.iml
@@ -6,6 +6,10 @@
       <excludeFolder url="file://$MODULE_DIR$/angel_jael/.pub" />
       <excludeFolder url="file://$MODULE_DIR$/angel_jael/build" />
     </content>
+    <content url="file://$MODULE_DIR$/build_jael">
+      <excludeFolder url="file://$MODULE_DIR$/build_jael/.pub" />
+      <excludeFolder url="file://$MODULE_DIR$/build_jael/build" />
+    </content>
     <content url="file://$MODULE_DIR$/jael">
       <excludeFolder url="file://$MODULE_DIR$/jael/.pub" />
       <excludeFolder url="file://$MODULE_DIR$/jael/build" />