diff --git a/tests/src/test/java/org/mozilla/javascript/tests/StackTraceTest.java b/tests/src/test/java/org/mozilla/javascript/tests/StackTraceTest.java
index 5abf43c1ae..04afb945fb 100644
--- a/tests/src/test/java/org/mozilla/javascript/tests/StackTraceTest.java
+++ b/tests/src/test/java/org/mozilla/javascript/tests/StackTraceTest.java
@@ -119,7 +119,7 @@ public void failureStackTraceV8() {
 
     private static void runWithExpectedStackTrace(
             final String _source, final String _expectedStackTrace) {
-        Utils.runWithOptimizationLevel(
+        Utils.runWithMode(
                 cx -> {
                     final Scriptable scope = cx.initStandardObjects();
                     try {
@@ -130,6 +130,6 @@ private static void runWithExpectedStackTrace(
                     }
                     throw new RuntimeException("Exception expected!");
                 },
-                -1);
+                true);
     }
 }
diff --git a/tests/src/test/java/org/mozilla/javascript/tests/es6/NumericSeparatorTest.java b/tests/src/test/java/org/mozilla/javascript/tests/es6/NumericSeparatorTest.java
index 50b9a38fce..0ba3407e5a 100644
--- a/tests/src/test/java/org/mozilla/javascript/tests/es6/NumericSeparatorTest.java
+++ b/tests/src/test/java/org/mozilla/javascript/tests/es6/NumericSeparatorTest.java
@@ -22,7 +22,7 @@ public void numericAtEndOneDigit() {
     /** Special Tokenizer test for numeric constant at end. */
     @Test
     public void numericAtEndManyDigits() {
-        Utils.runWithOptimizationLevel(
+        Utils.runWithMode(
                 cx -> {
                     cx.setLanguageVersion(Context.VERSION_ES6);
                     ScriptableObject scope = cx.initStandardObjects();
@@ -32,10 +32,10 @@ public void numericAtEndManyDigits() {
 
                     return null;
                 },
-                -1);
+                true);
 
         // the byte code generator adds a cast to integer
-        Utils.runWithOptimizationLevel(
+        Utils.runWithMode(
                 cx -> {
                     cx.setLanguageVersion(Context.VERSION_ES6);
                     ScriptableObject scope = cx.initStandardObjects();
@@ -45,19 +45,7 @@ public void numericAtEndManyDigits() {
 
                     return null;
                 },
-                0);
-
-        Utils.runWithOptimizationLevel(
-                cx -> {
-                    cx.setLanguageVersion(Context.VERSION_ES6);
-                    ScriptableObject scope = cx.initStandardObjects();
-
-                    Object result = cx.evaluateString(scope, "1234", "test", 1, null);
-                    assertEquals(1234, result);
-
-                    return null;
-                },
-                1);
+                false);
     }
 
     /** Special Tokenizer test for numeric separator constant at end. */
diff --git a/testutils/src/main/java/org/mozilla/javascript/tests/Utils.java b/testutils/src/main/java/org/mozilla/javascript/tests/Utils.java
index a70b8e0c1a..029df4216e 100644
--- a/testutils/src/main/java/org/mozilla/javascript/tests/Utils.java
+++ b/testutils/src/main/java/org/mozilla/javascript/tests/Utils.java
@@ -52,30 +52,11 @@ public static void runWithAllOptimizationLevels(
         runWithMode(contextFactory, action, true);
     }
 
-    /** Runs the provided action at the given optimization level */
-    public static void runWithOptimizationLevel(
-            final ContextAction<?> action, final int optimizationLevel) {
-        runWithOptimizationLevel(new ContextFactory(), action, optimizationLevel);
-    }
-
     /** Runs the provided action at the given interpretation mode */
     public static void runWithMode(final ContextAction<?> action, final boolean interpretedMode) {
         runWithMode(new ContextFactory(), action, interpretedMode);
     }
 
-    /** Runs the provided action at the given optimization level */
-    @SuppressWarnings("deprecation")
-    public static void runWithOptimizationLevel(
-            final ContextFactory contextFactory,
-            final ContextAction<?> action,
-            final int optimizationLevel) {
-
-        try (final Context cx = contextFactory.enterContext()) {
-            cx.setOptimizationLevel(optimizationLevel);
-            action.run(cx);
-        }
-    }
-
     /** Runs the provided action at the given interpretation mode */
     public static void runWithMode(
             final ContextFactory contextFactory,