diff --git a/ormar/queryset/utils.py b/ormar/queryset/utils.py
index 5520f67..9c84817 100644
--- a/ormar/queryset/utils.py
+++ b/ormar/queryset/utils.py
@@ -17,10 +17,12 @@ if TYPE_CHECKING:  # pragma no cover
     from ormar import Model, BaseField
 
 
-def to_str(val: Union[bytes, str]):
+def to_str(val: Union[bytes, str, int]):
     """ convert bytes to str simply """
     if isinstance(val, bytes):
         return val.decode("utf-8")
+    elif isinstance(val, str):
+        return val
     return str(val)
 
 
diff --git a/tests/test_queries/test_utils.py b/tests/test_queries/test_utils.py
index 893d4a9..8f2fac4 100644
--- a/tests/test_queries/test_utils.py
+++ b/tests/test_queries/test_utils.py
@@ -12,3 +12,4 @@ def test_to_str():
     assert isinstance(expected_bytes, bytes)
 
     assert isinstance(to_str(expected_bytes), str)
+    assert "1" == to_str(1)