diff --git a/src/esmockErr.js b/src/esmockErr.js
index ef016ef6..a43a590c 100644
--- a/src/esmockErr.js
+++ b/src/esmockErr.js
@@ -8,8 +8,12 @@ const errMissingLoader = () =>
   new Error('the loader chain process must include esmock. '
     + 'start the process using --loader=esmock.')
 
+const errModuleIdNoDefs = (moduleId, parent) =>
+  new Error(`no mocks provided for module: "${moduleId}" (used by ${parent}`)
+
 export default {
   errModuleIdNotFound,
   errModuleIdNotMocked,
-  errMissingLoader
+  errMissingLoader,
+  errModuleIdNoDefs
 }
diff --git a/src/esmockModule.js b/src/esmockModule.js
index 8763b254..1342e6bb 100644
--- a/src/esmockModule.js
+++ b/src/esmockModule.js
@@ -129,12 +129,18 @@ const esmockModule = async (moduleId, parent, defs, gdefs, opt) => {
   if (!moduleFileURL)
     throw esmockErr.errModuleIdNotFound(moduleId, parent)
 
+  const gkeys = gdefs ? Object.keys(gdefs) : []
+  const dkeys = defs ? Object.keys(defs) : []
+  if (opt.strict === 3 && !gkeys.length && !dkeys.length) {
+    throw esmockErr.errModuleIdNoDefs(moduleId, parent)
+  }
+
   const treeid = typeof opt.id === 'number' ? opt.id : nextId()
   const treeidspec = `${moduleFileURL}?key=${treeid}&strict=${opt.strict}?` + [
-    'esmkgdefs=' + (gdefs && (await esmockModuleId(
-      parent, treeid, gdefs, Object.keys(gdefs), opt)).join('#-#') || 0),
-    'esmkdefs=', (defs && (await esmockModuleId(
-      parent, treeid, defs, Object.keys(defs), opt)).join('#-#') || 0)
+    'esmkgdefs=' + (gkeys.length && (await esmockModuleId(
+      parent, treeid, gdefs, gkeys, opt)).join('#-#') || 0),
+    'esmkdefs=', (dkeys.length && (await esmockModuleId(
+      parent, treeid, defs, dkeys, opt)).join('#-#') || 0)
   ].join('#-#')
 
   esmockTreeIdSet(String(treeid), treeidspec)
diff --git a/tests/local/strictest.js b/tests/local/strictest.js
index a4558bb2..30d13100 100644
--- a/tests/local/strictest.js
+++ b/tests/local/strictest.js
@@ -1,4 +1,4 @@
-import { log } from "console";
-import { basename } from "path";
+import { log } from "console"
+import { basename } from "path"
 
-log(basename(import.meta.url));
+log(basename(import.meta.url))
diff --git a/tests/tests-node/esmock.node.test.js b/tests/tests-node/esmock.node.test.js
index 388485c2..8b7904ff 100644
--- a/tests/tests-node/esmock.node.test.js
+++ b/tests/tests-node/esmock.node.test.js
@@ -437,14 +437,14 @@ test('should throw error when strict mock definition not found', async () => {
 test('should error when "strictest" called with defs: {}', async () => {
   await assert.rejects(async () => esmock.strictest(
     '../local/strictest.js', {}
-  ));
-});
+  ))
+})
 
 test('should error when "strictest" called with defs: undefined', async () => {
   await assert.rejects(async () => esmock.strictest(
     '../local/strictest.js'
-  ));
-});
+  ))
+})
 
 test('should error when "strictest" mock tree module not mocked', async () => {
   const strictestTree = await esmock.strictest(