diff --git a/src/cmd.js b/src/cmd.js
index 6bc4805..0949701 100644
--- a/src/cmd.js
+++ b/src/cmd.js
@@ -1,4 +1,4 @@
-import {map_object, pick_keys, collect_nodes_with_parents, uniq} 
+import {map_object, filter_object, pick_keys, collect_nodes_with_parents, uniq} 
   from './utils.js'
 import {
   is_eq, is_child, ancestry, ancestry_inc, map_tree,
@@ -105,6 +105,7 @@ const run_code = (s, index, dirty_files) => {
       external_imports.some(i => state.external_imports_cache[i] == null)
     )
   ) {
+    // Trigger loading of external modules
     return {...state, 
       loading_external_imports_state: {
         index,
@@ -112,10 +113,16 @@ const run_code = (s, index, dirty_files) => {
       }
     }
   } else {
+    // Modules were loaded and cached, proceed
     return external_imports_loaded(
       state, 
       state, 
-      state.external_imports_cache, 
+      state.external_imports_cache == null
+      ? null
+      : filter_object(
+          state.external_imports_cache,
+          (module_name, module) => external_imports.includes(module_name)
+        ),
       index
     )
   }
diff --git a/test/test.js b/test/test.js
index 9fe936c..ef67200 100644
--- a/test/test.js
+++ b/test/test.js
@@ -951,6 +951,34 @@ export const tests = [
     )
   }),
 
+  test('module external cache invalidation bug', () => {
+    const code = `
+      // external
+      import {foo_var} from 'foo.js'
+    `
+    const initial = test_initial_state(code)
+
+    // simulate module load error
+    const next = COMMANDS.external_imports_loaded(initial, initial, {
+      'foo.js': {
+        ok: false,
+        error: new Error('Failed to resolve module'),
+      }
+    })
+
+    const edited = ``
+
+    // edit code
+    const {state, effects} = COMMANDS.input(
+      next, 
+      edited, 
+      0,
+    )
+
+    assert_equal(state.parse_result.ok, true)
+  }),
+
+
   // Static analysis
 
   test('undeclared', () => {