diff --git a/lib/internal/util/comparisons.js b/lib/internal/util/comparisons.js
index 222bb936722cb6..1598e7f9136ace 100644
--- a/lib/internal/util/comparisons.js
+++ b/lib/internal/util/comparisons.js
@@ -147,7 +147,11 @@ function isIdenticalTypedArrayType(a, b) {
       return check(b);
     }
   }
-  return false;
+  /* c8 ignore next */
+  assert.fail(
+    `Unknown TypedArray type checking ${a[SymbolToStringTag]} ${a}\n` +
+    `and ${b[SymbolToStringTag]} ${b}`
+  );
 }
 
 // Notes: Type tags are historical [[Class]] properties that can be set by