diff --git a/src/org/mozilla/javascript/NativeArray.java b/src/org/mozilla/javascript/NativeArray.java
index 883a4584b0..e986757ff5 100644
--- a/src/org/mozilla/javascript/NativeArray.java
+++ b/src/org/mozilla/javascript/NativeArray.java
@@ -351,7 +351,7 @@ public Object execIdCall(IdFunctionObject f, Context cx, Scriptable scope,
                 return js_lastIndexOf(cx, scope, thisObj, args);
 
               case Id_includes:
-                return Boolean.valueOf(((long) js_indexOf(cx, scope, thisObj, args)) > -1);
+                return js_includes(cx, scope, thisObj, args);
 
               case Id_fill:
                 return js_fill(cx, scope, thisObj, args);
@@ -1711,6 +1711,59 @@ else if (start < 0)
         return NEGATIVE_ONE;
     }
 
+    /*
+       See ECMA-262 22.1.3.13
+    */
+    private static Boolean js_includes(Context cx, Scriptable scope, Scriptable thisObj, Object[] args) {
+        Object compareTo = args.length > 0 ? args[0] : Undefined.instance;
+
+        Scriptable o = ScriptRuntime.toObject(cx, scope, thisObj);
+        long len = ScriptRuntime.toLength(new Object[]{getProperty(thisObj, "length")}, 0);
+        if (len == 0) return Boolean.FALSE;
+
+        long k;
+        if (args.length < 2) {
+            k = 0;
+        } else {
+            k = (long) ScriptRuntime.toInteger(args[1]);
+            if (k < 0) {
+                k += len;
+                if (k < 0)
+                    k = 0;
+            }
+            if (k > len - 1) return Boolean.FALSE;
+        }
+        if (o instanceof NativeArray) {
+            NativeArray na = (NativeArray) o;
+            if (na.denseOnly) {
+                Scriptable proto = na.getPrototype();
+                for (int i = (int) k; i < len; i++) {
+                    Object elementK = na.dense[i];
+                    if (elementK == NOT_FOUND && proto != null) {
+                        elementK = ScriptableObject.getProperty(proto, i);
+                    }
+                    if (elementK == NOT_FOUND) {
+                        elementK = Undefined.instance;
+                    }
+                    if (ScriptRuntime.sameZero(elementK, compareTo)) {
+                        return Boolean.TRUE;
+                    }
+                }
+                return Boolean.FALSE;
+            }
+        }
+        for (; k < len; k++) {
+            Object elementK = getRawElem(o, k);
+            if (elementK == NOT_FOUND) {
+                elementK = Undefined.instance;
+            }
+            if (ScriptRuntime.sameZero(elementK, compareTo)) {
+                return Boolean.TRUE;
+            }
+        }
+        return Boolean.FALSE;
+    }
+
     private static Object js_fill(Context cx, Scriptable scope, Scriptable thisObj, Object[] args)
     {
         Scriptable o = ScriptRuntime.toObject(cx, scope, thisObj);
diff --git a/testsrc/test262.properties b/testsrc/test262.properties
index d8cab04c27..0c3a655c3f 100644
--- a/testsrc/test262.properties
+++ b/testsrc/test262.properties
@@ -90,22 +90,6 @@ built-ins/Array
     ! prototype/Symbol.unscopables/value.js
     # Not throwing properly on unwritable
     ! prototype/copyWithin/return-abrupt-from-delete-target.js
-    # No "valueOf" yet.
-    ! prototype/includes/fromIndex-equal-or-greater-length-returns-false.js
-    ! prototype/includes/fromIndex-infinity.js
-    ! prototype/includes/fromIndex-minus-zero.js
-    ! prototype/includes/get-prop.js
-    ! prototype/includes/length-boundaries.js
-    ! prototype/includes/length-zero-returns-false.js
-    ! prototype/includes/no-arg.js
-    ! prototype/includes/samevaluezero.js
-    ! prototype/includes/search-found-returns-true.js
-    ! prototype/includes/search-not-found-returns-false.js
-    ! prototype/includes/sparse.js
-    ! prototype/includes/tointeger-fromindex.js
-    ! prototype/includes/tolength-length.js
-    ! prototype/includes/using-fromindex.js
-    ! prototype/includes/values-are-not-cached.js
 
     # Expects a particular string value
     ! prototype/Symbol.iterator.js