diff --git a/src/dstack/_internal/server/routers/repos.py b/src/dstack/_internal/server/routers/repos.py
index 3c5b59857d..32e59f6317 100644
--- a/src/dstack/_internal/server/routers/repos.py
+++ b/src/dstack/_internal/server/routers/repos.py
@@ -1,7 +1,6 @@
 from typing import List, Tuple
 
 from fastapi import APIRouter, Depends, Request, UploadFile
-from humanize import naturalsize
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from dstack._internal.core.errors import ResourceNotExistsError, ServerClientError
@@ -20,6 +19,7 @@
     get_base_api_additional_responses,
     get_request_size,
 )
+from dstack._internal.utils.common import sizeof_fmt
 
 router = APIRouter(
     prefix="/api/project/{project_name}/repos",
@@ -98,10 +98,15 @@ async def upload_code(
 ):
     request_size = get_request_size(request)
     if SERVER_CODE_UPLOAD_LIMIT > 0 and request_size > SERVER_CODE_UPLOAD_LIMIT:
+        diff_size_fmt = sizeof_fmt(request_size)
+        limit_fmt = sizeof_fmt(SERVER_CODE_UPLOAD_LIMIT)
+        if diff_size_fmt == limit_fmt:
+            diff_size_fmt = f"{request_size}B"
+            limit_fmt = f"{SERVER_CODE_UPLOAD_LIMIT}B"
         raise ServerClientError(
-            f"Repo diff size is {naturalsize(request_size)}, which exceeds the limit of "
-            f"{naturalsize(SERVER_CODE_UPLOAD_LIMIT)}. Use .gitignore to exclude large files from the repo. This "
-            f"limit can be modified by setting the DSTACK_SERVER_CODE_UPLOAD_LIMIT environment variable"
+            f"Repo diff size is {diff_size_fmt}, which exceeds the limit of {limit_fmt}."
+            " Use .gitignore to exclude large files from the repo."
+            " This limit can be modified by setting the DSTACK_SERVER_CODE_UPLOAD_LIMIT environment variable."
         )
     _, project = user_project
     await repos.upload_code(
diff --git a/src/tests/_internal/utils/test_common.py b/src/tests/_internal/utils/test_common.py
index a10e3f7a3a..ed9ef99168 100644
--- a/src/tests/_internal/utils/test_common.py
+++ b/src/tests/_internal/utils/test_common.py
@@ -11,6 +11,7 @@
     make_proxy_url,
     parse_memory,
     pretty_date,
+    sizeof_fmt,
     split_chunks,
 )
 
@@ -211,3 +212,26 @@ def test_concat_url_path(a: str, b: str, result: str) -> None:
 )
 def test_make_proxy_url(server_url, proxy_url, expected_url):
     assert make_proxy_url(server_url, proxy_url) == expected_url
+
+
+class TestSizeofFmt:
+    @pytest.mark.parametrize(
+        ("num", "suffix", "expected"),
+        [
+            (0, "B", "0.0B"),
+            (1023, "B", "1023.0B"),
+            (1024, "B", "1.0KiB"),
+            (1536, "B", "1.5KiB"),
+            (1048576, "B", "1.0MiB"),
+            (1073741824, "B", "1.0GiB"),
+            (1099511627776, "B", "1.0TiB"),
+            (1125899906842624, "B", "1.0PiB"),
+            (1152921504606846976, "B", "1.0EiB"),
+            (1180591620717411303424, "B", "1.0ZiB"),
+            (1208925819614629174706176, "B", "1.0YiB"),
+            (2000, "", "2.0Ki"),
+            (3000000, "Hz", "2.9MiHz"),
+        ],
+    )
+    def test_sizeof_fmt(self, num: int, suffix: str, expected: str) -> None:
+        assert sizeof_fmt(num, suffix) == expected