diff --git a/jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c b/jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c
index 82532a667..7d28e190d 100644
--- a/jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c
+++ b/jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c
@@ -2491,14 +2491,13 @@ ecma_builtin_array_prototype_object_copy_within (const ecma_value_t args[], /**<
     }
   }
 
-  if (target >= len || start >= end || end == 0)
+  ecma_length_t count = JERRY_MIN (end - start, len - target);
+  if (end <= start || len <= target) /* count <= 0 check, but variables are unsigned */
   {
     ecma_ref_object (obj_p);
     return ecma_make_object_value (obj_p);
   }
 
-  ecma_length_t count = JERRY_MIN (end - start, len - target);
-
   bool forward = true;
 
   if (start < target && target < start + count)
@@ -2511,12 +2510,13 @@ ecma_builtin_array_prototype_object_copy_within (const ecma_value_t args[], /**<
   if (ecma_op_object_is_fast_array (obj_p))
   {
     ecma_extended_object_t *ext_obj_p = (ecma_extended_object_t *) obj_p;
+    const uint32_t actual_length = ext_obj_p->u.array.length;
 
-    if (ext_obj_p->u.array.u.hole_count < ECMA_FAST_ARRAY_HOLE_ONE)
+    if (ext_obj_p->u.array.u.hole_count < ECMA_FAST_ARRAY_HOLE_ONE
+        && ((forward && (target + count - 1 < actual_length)) || (!forward && (target < actual_length))))
     {
       if (obj_p->u1.property_list_cp != JMEM_CP_NULL)
       {
-        count = JERRY_MIN (ext_obj_p->u.array.length, count);
         ecma_value_t *buffer_p = ECMA_GET_NON_NULL_POINTER (ecma_value_t, obj_p->u1.property_list_cp);
 
         for (; count > 0; count--)
diff --git a/tests/jerry/es.next/array-prototype-copywithin.js b/tests/jerry/es.next/array-prototype-copywithin.js
index ddf1ed4db..2d5dab162 100644
--- a/tests/jerry/es.next/array-prototype-copywithin.js
+++ b/tests/jerry/es.next/array-prototype-copywithin.js
@@ -95,7 +95,6 @@ var value = array.copyWithin(0, {
         array.length = 0;
     }
 })
-
 array_check(value, []);
 
 // Extend the buffer
@@ -105,7 +104,6 @@ var value = array.copyWithin(1, {
         array.length = 6;
     }
 })
-
 array_check(value, [1, 1, 2, undefined, undefined, undefined]);
 
 // Reduce the buffer
@@ -115,5 +113,18 @@ var value = array.copyWithin(4, 2, {
         array.length = 3;
     }
 })
-
 array_check(value, [1, 2, 3]);
+
+// Reduce the buffer and extend the buffer
+var array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+var value = array.copyWithin(7, {
+    valueOf: function() {
+        array.length = 5;
+    }
+})
+array_check(value, [1, 2, 3, 4, 5, , , 1, 2, 3]);
+
+// Copy with overlapping (backward copy)
+var array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+var value = array.copyWithin(0, 2, 8)
+array_check(value, [3, 4, 5, 6, 7, 8, 7, 8, 9, 10]);
diff --git a/tests/jerry/es.next/regression-test-issue-4146.js b/tests/jerry/es.next/regression-test-issue-4146.js
index f136f8b28..bc5548cbb 100644
--- a/tests/jerry/es.next/regression-test-issue-4146.js
+++ b/tests/jerry/es.next/regression-test-issue-4146.js
@@ -32,7 +32,7 @@ Array.prototype.equals = function (array) {
 
 function longDenseArray(){
         var a = [0];
-        for(var i = 0; i < 200; i++){
+        for(var i = 0; i < 60; i++){
                 a[i] = i;
         }
         return a;
@@ -43,7 +43,8 @@ function shorten(){
         return 1;
 }
 
+var array = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,,,,,,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19];
 var currArray = longDenseArray();
-assert (currArray.copyWithin (200, {valueOf: shorten}).length == 20)
-var array = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19];
-assert (currArray.copyWithin(200, {valueOf: shorten}).equals (array))
+currArray.copyWithin(25, {valueOf: shorten})
+assert (currArray.length == 44)
+assert (currArray.equals (array))
diff --git a/tests/test262-esnext-excludelist.xml b/tests/test262-esnext-excludelist.xml
index 894b3bb3b..086105064 100644
--- a/tests/test262-esnext-excludelist.xml
+++ b/tests/test262-esnext-excludelist.xml
@@ -142,8 +142,6 @@
   <test id="built-ins/Array/proto-from-ctor-realm-zero.js"><reason></reason></test>
   <test id="built-ins/Array/prototype/concat/create-proto-from-ctor-realm-array.js"><reason></reason></test>
   <test id="built-ins/Array/prototype/concat/create-proto-from-ctor-realm-non-array.js"><reason></reason></test>
-  <test id="built-ins/Array/prototype/copyWithin/coerced-values-start-change-start.js"><reason></reason></test>
-  <test id="built-ins/Array/prototype/copyWithin/coerced-values-start-change-target.js"><reason></reason></test>
   <test id="built-ins/Array/prototype/filter/create-proto-from-ctor-realm-array.js"><reason></reason></test>
   <test id="built-ins/Array/prototype/filter/create-proto-from-ctor-realm-non-array.js"><reason></reason></test>
   <test id="built-ins/Array/prototype/map/create-proto-from-ctor-realm-array.js"><reason></reason></test>