diff --git a/test/mjsunit/compiler/array-multiple-receiver-maps.js b/test/mjsunit/compiler/array-multiple-receiver-maps.js
index 56c505a9e4..0f8efd9c0c 100644
--- a/test/mjsunit/compiler/array-multiple-receiver-maps.js
+++ b/test/mjsunit/compiler/array-multiple-receiver-maps.js
@@ -35,7 +35,7 @@ function runTest(f, message, mkICTraining, deoptArg, speculationCheck) {
       for (let a of t3) {
         message += " for args " + JSON.stringify(a) + " should have been optimized";
         f(a.arr, () => a.el);
-        assertOptimized(f, undefined, message);
+        assertOptimized(f, message);
       }
     } else {
       // Trigger deopt, causing no-speculation bit to be set.
@@ -46,18 +46,18 @@ function runTest(f, message, mkICTraining, deoptArg, speculationCheck) {
       message_unoptimized = message + " should have been unoptimized"
       message_optimized = message + " should have been optimized"
       f(a1.darr, () => a1.del);
-      assertUnoptimized(f, undefined, message_unoptimized);
+      assertUnoptimized(f, message_unoptimized);
       if (speculationCheck) {
         %PrepareFunctionForOptimization(f);
         %OptimizeFunctionOnNextCall(f);
         f(a2.darr, () => a2.del);
-        assertUnoptimized(f, undefined, message_unoptimized);
+        assertUnoptimized(f, message_unoptimized);
       }
       %PrepareFunctionForOptimization(f);
       %OptimizeFunctionOnNextCall(f);
       // No speculation should protect against further deopts.
       f(a3.darr, () => a3.del);
-      assertOptimized(f, undefined,  message_optimized);
+      assertOptimized(f,  message_optimized);
     }
   }
 
diff --git a/test/mjsunit/compiler/regress-905555-2.js b/test/mjsunit/compiler/regress-905555-2.js
index 593a1728bc..e656a26dc8 100644
--- a/test/mjsunit/compiler/regress-905555-2.js
+++ b/test/mjsunit/compiler/regress-905555-2.js
@@ -22,6 +22,6 @@ delete this.global;
 %FinalizeOptimization();
 
 // boom should be deoptimized because the global property cell has changed.
-assertUnoptimized(boom, "sync");
+assertUnoptimized(boom);
 
 assertThrows(boom);
diff --git a/test/mjsunit/compiler/stress-deopt-count-1.js b/test/mjsunit/compiler/stress-deopt-count-1.js
index 1dab8631eb..4caa55ece6 100644
--- a/test/mjsunit/compiler/stress-deopt-count-1.js
+++ b/test/mjsunit/compiler/stress-deopt-count-1.js
@@ -15,7 +15,7 @@ f(0);
 %OptimizeFunctionOnNextCall(f);
 
 f(1);
-assertOptimized(f, undefined, undefined, false);
+assertOptimized(f, undefined, false);
 
 f(1);
-assertOptimized(f, undefined, undefined, false);
+assertOptimized(f, undefined, false);
diff --git a/test/mjsunit/compiler/stress-deopt-count-2.js b/test/mjsunit/compiler/stress-deopt-count-2.js
index 3ddf05cc83..b64d0f9530 100644
--- a/test/mjsunit/compiler/stress-deopt-count-2.js
+++ b/test/mjsunit/compiler/stress-deopt-count-2.js
@@ -18,33 +18,33 @@ f(1);
 // stress_deopt_count == 6
 
 f(1);
-assertOptimized(f, undefined, undefined, false);
+assertOptimized(f, undefined, false);
 
 // stress_deopt_count == 4
 
 f(1);
-assertOptimized(f, undefined, undefined, false);
+assertOptimized(f, undefined, false);
 
 // stress_deopt_count == 2
 
 f(1);
 // deopt & counter reset
-assertUnoptimized(f, undefined, undefined, false);
+assertUnoptimized(f, undefined, false);
 
 // stress_deopt_count == 6
 
 %PrepareFunctionForOptimization(f);
 %OptimizeFunctionOnNextCall(f);
 f(1);
-assertOptimized(f, undefined, undefined, false);
+assertOptimized(f, undefined, false);
 
 // stress_deopt_count == 4
 
 f(1);
-assertOptimized(f, undefined, undefined, false);
+assertOptimized(f, undefined, false);
 
 // stress_deopt_count == 2
 
 f(1);
 // deopt & counter reset
-assertUnoptimized(f, undefined, undefined, false);
+assertUnoptimized(f, undefined, false);
diff --git a/test/mjsunit/concurrent-initial-prototype-change-1.js b/test/mjsunit/concurrent-initial-prototype-change-1.js
index 6660e7a779..0486d8d3a5 100644
--- a/test/mjsunit/concurrent-initial-prototype-change-1.js
+++ b/test/mjsunit/concurrent-initial-prototype-change-1.js
@@ -52,6 +52,6 @@ assertUnoptimized(f1);
 // Sync with background thread to conclude optimization, which bails out
 // due to map dependency.
 %FinalizeOptimization();
-assertUnoptimized(f1, "sync");
+assertUnoptimized(f1);
 // Clear type info for stress runs.
 %ClearFunctionFeedback(f1);
diff --git a/test/mjsunit/es6/array-iterator-turbo.js b/test/mjsunit/es6/array-iterator-turbo.js
index 8df9ccaa56..6f82f09c78 100644
--- a/test/mjsunit/es6/array-iterator-turbo.js
+++ b/test/mjsunit/es6/array-iterator-turbo.js
@@ -107,13 +107,13 @@ let tests = {
       %OptimizeFunctionOnNextCall(fn);
       fn(array);
 
-      assertOptimized(fn, '', key);
+      assertOptimized(fn, key);
       assertEquals(expected, fn(array), key);
-      assertOptimized(fn, '', key);
+      assertOptimized(fn, key);
 
       // Check no deopt when another array with the same map is used
       assertTrue(%HaveSameMap(array, array2), key);
-      assertOptimized(fn, '', key);
+      assertOptimized(fn, key);
       assertEquals(expected2, fn(array2), key);
 
       // CheckMaps bailout
@@ -121,7 +121,7 @@ let tests = {
           [1, 2, 3], 2, { enumerable: false, configurable: false,
                           get() { return 7; } });
       fn(newArray);
-      assertUnoptimized(fn, '', key);
+      assertUnoptimized(fn, key);
     }
   },
 
@@ -210,12 +210,12 @@ let tests = {
       %OptimizeFunctionOnNextCall(sum);
       assertEquals(expected, sum(array), key);
 
-      assertOptimized(sum, '', key);
+      assertOptimized(sum, key);
 
       // Not deoptimized when called on typed array of same type / map
       assertTrue(%HaveSameMap(array, array2));
       assertEquals(expected2, sum(array2), key);
-      assertOptimized(sum, '', key);
+      assertOptimized(sum, key);
 
       // Throw when detached
       let clone = new array.constructor(array);
diff --git a/test/mjsunit/mjsunit.js b/test/mjsunit/mjsunit.js
index 6a2180bf69..8c791ddba6 100644
--- a/test/mjsunit/mjsunit.js
+++ b/test/mjsunit/mjsunit.js
@@ -734,6 +734,7 @@ var prettyPrinted;
   assertUnoptimized = function assertUnoptimized(
       fun, name_opt, skip_if_maybe_deopted = true) {
     var opt_status = OptimizationStatus(fun);
+    name_opt = name_opt ?? fun.name;
     // Tests that use assertUnoptimized() do not make sense if --always-turbofan
     // option is provided. Such tests must add --no-always-turbofan to flags comment.
     assertFalse((opt_status & V8OptimizationStatus.kAlwaysOptimize) !== 0,
@@ -753,6 +754,7 @@ var prettyPrinted;
   assertOptimized = function assertOptimized(
       fun, name_opt, skip_if_maybe_deopted = true) {
     var opt_status = OptimizationStatus(fun);
+    name_opt = name_opt ?? fun.name;
     // Tests that use assertOptimized() do not make sense for Lite mode where
     // optimization is always disabled, explicitly exit the test with a warning.
     if (opt_status & V8OptimizationStatus.kLiteMode) {