diff --git a/CHANGES/1139.feature.rst b/CHANGES/1139.feature.rst
new file mode 100644
index 000000000..3bcc26e12
--- /dev/null
+++ b/CHANGES/1139.feature.rst
@@ -0,0 +1 @@
+Loosen restriction on integers as query string values to allow classes that implement ``__int__`` -- by :user:`bdraco`.
diff --git a/tests/test_update_query.py b/tests/test_update_query.py
index 26ccda62a..e652f457e 100644
--- a/tests/test_update_query.py
+++ b/tests/test_update_query.py
@@ -249,6 +249,19 @@ class IntEnum(int, enum.Enum):
     assert str(url2) == "http://example.com/path?a=1"
 
 
+def test_with_class_that_implements__int__():
+    """Allow classes that implement __int__ to be used in query strings."""
+
+    class myint:
+
+        def __int__(self):
+            return 84
+
+    url = URL("http://example.com/path")
+    url2 = url.with_query(a=myint())
+    assert str(url2) == "http://example.com/path?a=84"
+
+
 def test_with_float_enum():
     class FloatEnum(float, enum.Enum):
         A = 1.1
diff --git a/yarl/_url.py b/yarl/_url.py
index 22f41da21..b6a4530d1 100644
--- a/yarl/_url.py
+++ b/yarl/_url.py
@@ -12,6 +12,7 @@
     Iterable,
     Iterator,
     List,
+    SupportsInt,
     Tuple,
     TypedDict,
     TypeVar,
@@ -1185,9 +1186,7 @@ def _query_var(v: QueryVariable) -> str:
             if math.isnan(v):
                 raise ValueError("float('nan') is not supported")
             return str(float(v))
-        if cls is not bool and issubclass(cls, int):
-            if TYPE_CHECKING:
-                assert isinstance(v, int)
+        if cls is not bool and isinstance(cls, SupportsInt):
             return str(int(v))
         raise TypeError(
             "Invalid variable type: value "