diff --git a/appengine/blockly_compressed.js b/appengine/blockly_compressed.js
index dc118dfbe..837d6bb35 100644
--- a/appengine/blockly_compressed.js
+++ b/appengine/blockly_compressed.js
@@ -6,6 +6,6 @@ var msg = 'Compiled Blockly files should be loaded from https://unpkg.com/blockl
 console.log(msg);
 try {
   alert(msg);
-} catch (_e) {
+} catch {
   // Can't alert?  Probably node.js.
 }
diff --git a/scripts/gulpfiles/build_tasks.js b/scripts/gulpfiles/build_tasks.js
index 27a02cf30..a00c1b17d 100644
--- a/scripts/gulpfiles/build_tasks.js
+++ b/scripts/gulpfiles/build_tasks.js
@@ -699,7 +699,7 @@ function buildAdvancedCompilationTest() {
   // a later browser-based test won't check it should the compile fail.
   try {
     fs.unlinkSync('./tests/compile/main_compressed.js');
-  } catch (_e) {
+  } catch {
     // Probably it didn't exist.
   }
 
diff --git a/tests/compile/main.js b/tests/compile/main.js
index 9144c4d3b..bbca3909f 100644
--- a/tests/compile/main.js
+++ b/tests/compile/main.js
@@ -47,7 +47,7 @@ window['healthCheck'] = function() {
     const blockCount =
         getMainWorkspace().getFlyout().getWorkspace().getTopBlocks().length;
     return (blockCount > 5 && blockCount < 100);
-  } catch (_e) {
+  } catch {
     return false;
   }
 };