diff --git a/backend/posix/posix.go b/backend/posix/posix.go
index 69805b9b..c357e2d1 100644
--- a/backend/posix/posix.go
+++ b/backend/posix/posix.go
@@ -3844,8 +3844,8 @@ func (p *Posix) CopyObject(ctx context.Context, input s3response.CopyObjectInput
 		}
 
 		if string(vId) != srcVersionId {
-			srcBucket = filepath.Join(p.versioningDir, srcBucket)
-			srcObject = filepath.Join(genObjVersionKey(srcObject), srcVersionId)
+			srcBucket = joinPathWithTrailer(p.versioningDir, srcBucket)
+			srcObject = joinPathWithTrailer(genObjVersionKey(srcObject), srcVersionId)
 		}
 	}
 
@@ -3857,7 +3857,7 @@ func (p *Posix) CopyObject(ctx context.Context, input s3response.CopyObjectInput
 		return nil, fmt.Errorf("stat bucket: %w", err)
 	}
 
-	objPath := filepath.Join(srcBucket, srcObject)
+	objPath := joinPathWithTrailer(srcBucket, srcObject)
 	f, err := os.Open(objPath)
 	if errors.Is(err, fs.ErrNotExist) || errors.Is(err, syscall.ENOTDIR) {
 		if p.versioningEnabled() && vEnabled {
@@ -3896,7 +3896,7 @@ func (p *Posix) CopyObject(ctx context.Context, input s3response.CopyObjectInput
 	var crc64nvme *string
 	var chType types.ChecksumType
 
-	dstObjdPath := filepath.Join(dstBucket, dstObject)
+	dstObjdPath := joinPathWithTrailer(dstBucket, dstObject)
 	if dstObjdPath == objPath {
 		if input.MetadataDirective == types.MetadataDirectiveCopy {
 			return &s3.CopyObjectOutput{}, s3err.GetAPIError(s3err.ErrInvalidCopyDest)
@@ -4917,3 +4917,11 @@ func getString(str *string) string {
 	}
 	return *str
 }
+
+func joinPathWithTrailer(paths ...string) string {
+	joined := filepath.Join(paths...)
+	if strings.HasSuffix(paths[len(paths)-1], "/") {
+		joined += "/"
+	}
+	return joined
+}
diff --git a/tests/integration/group-tests.go b/tests/integration/group-tests.go
index ad7a147b..12b12116 100644
--- a/tests/integration/group-tests.go
+++ b/tests/integration/group-tests.go
@@ -641,6 +641,8 @@ func TestPosix(s *S3Conf) {
 	PutObject_name_too_long(s)
 	HeadObject_name_too_long(s)
 	DeleteObject_name_too_long(s)
+	CopyObject_overwrite_same_dir_object(s)
+	CopyObject_overwrite_same_file_object(s)
 	DeleteObject_directory_not_empty(s)
 	// posix specific versioning tests
 	if !s.versioningEnabled {
@@ -912,6 +914,8 @@ func GetIntTests() IntTests {
 		"DeleteObject_non_existing_object":                                        DeleteObject_non_existing_object,
 		"DeleteObject_directory_object_noslash":                                   DeleteObject_directory_object_noslash,
 		"DeleteObject_name_too_long":                                              DeleteObject_name_too_long,
+		"CopyObject_overwrite_same_dir_object":                                    CopyObject_overwrite_same_dir_object,
+		"CopyObject_overwrite_same_file_object":                                   CopyObject_overwrite_same_file_object,
 		"DeleteObject_non_existing_dir_object":                                    DeleteObject_non_existing_dir_object,
 		"DeleteObject_directory_object":                                           DeleteObject_directory_object,
 		"DeleteObject_success":                                                    DeleteObject_success,
diff --git a/tests/integration/tests.go b/tests/integration/tests.go
index bfafc92f..0dcc2eb6 100644
--- a/tests/integration/tests.go
+++ b/tests/integration/tests.go
@@ -14635,6 +14635,52 @@ func DeleteObject_name_too_long(s *S3Conf) error {
 	})
 }
 
+func CopyObject_overwrite_same_dir_object(s *S3Conf) error {
+	testName := "CopyObject_overwrite_same_dir_object"
+	return actionHandler(s, testName, func(s3client *s3.Client, bucket string) error {
+		_, err := putObjects(s3client, []string{"foo/"}, bucket)
+		if err != nil {
+			return err
+		}
+
+		ctx, cancel := context.WithTimeout(context.Background(), shortTimeout)
+		_, err = s3client.CopyObject(ctx, &s3.CopyObjectInput{
+			Bucket:     &bucket,
+			Key:        getPtr("foo"),
+			CopySource: getPtr(fmt.Sprintf("%v/%v", bucket, "foo/")),
+		})
+		cancel()
+		if err := checkApiErr(err, s3err.GetAPIError(s3err.ErrExistingObjectIsDirectory)); err != nil {
+			return err
+		}
+
+		return nil
+	})
+}
+
+func CopyObject_overwrite_same_file_object(s *S3Conf) error {
+	testName := "CopyObject_overwrite_same_file_object"
+	return actionHandler(s, testName, func(s3client *s3.Client, bucket string) error {
+		_, err := putObjects(s3client, []string{"foo"}, bucket)
+		if err != nil {
+			return err
+		}
+
+		ctx, cancel := context.WithTimeout(context.Background(), shortTimeout)
+		_, err = s3client.CopyObject(ctx, &s3.CopyObjectInput{
+			Bucket:     &bucket,
+			Key:        getPtr("foo/"),
+			CopySource: getPtr(fmt.Sprintf("%v/%v", bucket, "foo")),
+		})
+		cancel()
+		if err := checkApiErr(err, s3err.GetAPIError(s3err.ErrObjectParentIsFile)); err != nil {
+			return err
+		}
+
+		return nil
+	})
+}
+
 // Versioning tests
 func PutBucketVersioning_non_existing_bucket(s *S3Conf) error {
 	testName := "PutBucketVersioning_non_existing_bucket"