diff --git a/CHANGELOG.md b/CHANGELOG.md
index 69d85bfc..e97d71ea 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ upcoming release can be found in [changelog.d](changelog.d).
   These means following breaking changes:
   - `b2` will no longer persists credentials and other secrets on disk if credentials were passed through `B2_*` environment variables. To explicitly persist them and keep using local cache for better performance, user can simply call `b2 account account`
   - `b2 ls` and `b2 rm` no longer accept two positional arguments, instead accepting only `B2 URI` (e.g. `b2://bucketName/path`)
+  - `-` is no longer supported as a valid filename, always being interpreted as standard input alias instead
 - Changed `sync` command exit status code from 0 to 1 if any warnings or errors were encountered during the operation.
 
 ### Fixed
diff --git a/b2/_internal/b2v3/registry.py b/b2/_internal/b2v3/registry.py
index 811e4197..400b7d33 100644
--- a/b2/_internal/b2v3/registry.py
+++ b/b2/_internal/b2v3/registry.py
@@ -92,6 +92,24 @@ class Ls(B2URIMustPointToFolderMixin, B2URIBucketNFolderNameArgMixin, BaseLs):
     ALLOW_ALL_BUCKETS = True
 
 
+class HyphenFilenameMixin:
+    def get_input_stream(self, filename):
+        if filename == '-' and os.path.exists('-'):
+            self._print_stderr(
+                "WARNING: Filename `-` won't be supported in the future and will always be treated as stdin alias."
+            )
+            return '-'
+        return super().get_input_stream(filename)
+
+
+class UploadUnboundStream(HyphenFilenameMixin, UploadUnboundStream):
+    __doc__ = UploadUnboundStream.__doc__
+
+
+class UploadFile(HyphenFilenameMixin, UploadFile):
+    __doc__ = UploadFile.__doc__
+
+
 B2.register_subcommand(AuthorizeAccount)
 B2.register_subcommand(CancelAllUnfinishedLargeFiles)
 B2.register_subcommand(CancelLargeFile)
diff --git a/b2/_internal/console_tool.py b/b2/_internal/console_tool.py
index 25e3a979..c7418f3e 100644
--- a/b2/_internal/console_tool.py
+++ b/b2/_internal/console_tool.py
@@ -3434,12 +3434,7 @@ def upload_file_kwargs_to_unbound_upload(self, **kwargs):
     def get_input_stream(self, filename: str) -> str | int | io.BinaryIO:
         """Get input stream IF filename points to a FIFO or stdin."""
         if filename == "-":
-            if os.path.exists('-'):
-                self._print_stderr(
-                    "WARNING: Filename `-` won't be supported in the future and will always be treated as stdin alias."
-                )
-            else:
-                return sys.stdin.buffer if platform.system() == "Windows" else sys.stdin.fileno()
+            return sys.stdin.buffer if platform.system() == "Windows" else sys.stdin.fileno()
         elif points_to_fifo(pathlib.Path(filename)):
             return filename
 
diff --git a/changelog.d/+hyphen_filename.fixed.md b/changelog.d/+hyphen_filename.fixed.md
new file mode 100644
index 00000000..2f467d3a
--- /dev/null
+++ b/changelog.d/+hyphen_filename.fixed.md
@@ -0,0 +1,2 @@
+Fix `-` handling in file upload commands - even if file with `-` name exists, the stdin will be chosen over it.
+This change affects `b2v4` (which is also aliased as `b2`), but not `b2v3` to keep backwards compatibility.
diff --git a/test/unit/console_tool/test_upload_file.py b/test/unit/console_tool/test_upload_file.py
index 6f4a65e8..44ad7750 100644
--- a/test/unit/console_tool/test_upload_file.py
+++ b/test/unit/console_tool/test_upload_file.py
@@ -10,7 +10,7 @@
 import os
 from test.helpers import skip_on_windows
 
-import b2
+import pytest
 
 
 def test_upload_file__file_info_src_last_modified_millis_and_headers(b2_cli, bucket, tmpdir):
@@ -77,10 +77,9 @@ def test_upload_file__named_pipe(b2_cli, bucket, tmpdir, bg_executor):
     writer.result(timeout=1)
 
 
+@pytest.mark.apiver(to_ver=3)
 def test_upload_file__hyphen_file_instead_of_stdin(b2_cli, bucket, tmpdir, monkeypatch):
     """Test `file upload` will upload file named `-` instead of stdin by default"""
-    # TODO remove this in v4
-    assert b2.__version__ < '4', "`-` filename should not be supported in next major version of CLI"
     filename = 'stdin.txt'
     content = "I'm very rare creature, a file named '-'"
     monkeypatch.chdir(str(tmpdir))
@@ -95,15 +94,44 @@ def test_upload_file__hyphen_file_instead_of_stdin(b2_cli, bucket, tmpdir, monke
         "size": len(content),
     }
     b2_cli.run(
-        ['file', 'upload', '--no-progress', 'my-bucket', '-', filename],
+        ['upload-file', '--no-progress', 'my-bucket', '-', filename],
         expected_json_in_stdout=expected_json,
         remove_version=True,
         expected_part_of_stdout=expected_stdout,
-        expected_stderr=
+        expected_stderr="WARNING: `upload-file` command is deprecated. Use `file upload` instead.\n"
         "WARNING: Filename `-` won't be supported in the future and will always be treated as stdin alias.\n",
     )
 
 
+@pytest.mark.apiver(from_ver=4)
+def test_upload_file__ignore_hyphen_file(b2_cli, bucket, tmpdir, monkeypatch, mock_stdin):
+    """Test `file upload` will upload stdin even when file named `-` is explicitly specified"""
+    content = "I'm very rare creature, a file named '-'"
+    monkeypatch.chdir(str(tmpdir))
+    source_file = tmpdir.join('-')
+    source_file.write(content)
+
+    content = "stdin input"
+    filename = 'stdin.txt'
+
+    expected_stdout = f'URL by file name: http://download.example.com/file/my-bucket/{filename}'
+    expected_json = {
+        "action": "upload",
+        "contentSha1": "2ce72aa159d1f190fddf295cc883f20c4787a751",
+        "fileName": filename,
+        "size": len(content),
+    }
+    mock_stdin.write(content)
+    mock_stdin.close()
+
+    b2_cli.run(
+        ['file', 'upload', '--no-progress', 'my-bucket', '-', filename],
+        expected_json_in_stdout=expected_json,
+        remove_version=True,
+        expected_part_of_stdout=expected_stdout,
+    )
+
+
 def test_upload_file__stdin(b2_cli, bucket, tmpdir, mock_stdin):
     """Test `file upload` stdin alias support"""
     content = "stdin input"