diff --git a/comtypes/automation.py b/comtypes/automation.py
index 26f84f47..f8bf6510 100644
--- a/comtypes/automation.py
+++ b/comtypes/automation.py
@@ -245,9 +245,6 @@ def _set_value(self, value):
         elif isinstance(value, bool):
             self.vt = VT_BOOL
             self._.VT_BOOL = value
-        elif isinstance(value, (int, c_int)):
-            self.vt = VT_I4
-            self._.VT_I4 = value
         elif isinstance(value, int):
             u = self._
             # try VT_I4 first.
@@ -264,12 +261,11 @@ def _set_value(self, value):
                     self.vt = VT_UI4
                     return
             # try VT_I8 next.
-            if value >= 0:
-                u.VT_I8 = value
-                if u.VT_I8 == value:
-                    # did work.
-                    self.vt = VT_I8
-                    return
+            u.VT_I8 = value
+            if u.VT_I8 == value:
+                # did work.
+                self.vt = VT_I8
+                return
             # try VT_UI8 next.
             if value >= 0:
                 u.VT_UI8 = value
@@ -277,9 +273,7 @@ def _set_value(self, value):
                     # did work.
                     self.vt = VT_UI8
                     return
-            # VT_R8 is last resort.
-            self.vt = VT_R8
-            u.VT_R8 = float(value)
+            raise TypeError(f"Cannot put {value!r} in VARIANT")
         elif isinstance(value, (float, c_double)):
             self.vt = VT_R8
             self._.VT_R8 = value
@@ -364,6 +358,9 @@ def _set_value(self, value):
         elif isinstance(value, c_uint):
             self.vt = VT_UI4
             self._.VT_UI4 = value
+        elif isinstance(value, c_int):
+            self.vt = VT_I4
+            self._.VT_I4 = value
         elif isinstance(value, c_float):
             self.vt = VT_R4
             self._.VT_R4 = value
diff --git a/comtypes/test/test_variant.py b/comtypes/test/test_variant.py
index dc1d5094..599cbf49 100644
--- a/comtypes/test/test_variant.py
+++ b/comtypes/test/test_variant.py
@@ -129,6 +129,39 @@ def test_integers(self):
         self.assertEqual(v.value, 1)
         self.assertIsInstance(v.value, int)
 
+    def test_vt_uix_range_boundaries(self):
+        MIN_VT_I4 = -(2**31)
+        MAX_VT_I4 = 2**31 - 1
+        MAX_VT_UI4 = 2**32 - 1
+        MIN_VT_I8 = -(2**63)
+        MAX_VT_I8 = 2**63 - 1
+        MAX_VT_UI8 = 2**64 - 1
+        for val, vt in [
+            (MIN_VT_I8, VT_I8),
+            (MIN_VT_I4 - 1, VT_I8),
+            (MIN_VT_I4, VT_I4),
+            (0, VT_I4),
+            (MAX_VT_I4, VT_I4),
+            (MAX_VT_I4 + 1, VT_UI4),
+            (MAX_VT_UI4, VT_UI4),
+            (MAX_VT_UI4 + 1, VT_I8),
+            (MAX_VT_I8, VT_I8),
+            (MAX_VT_I8 + 1, VT_UI8),
+            (MAX_VT_UI8, VT_UI8),
+        ]:
+            with self.subTest(val=val, vt=vt):
+                v = VARIANT()
+                v.value = val
+                self.assertEqual(v.value, val)
+                self.assertEqual(v.vt, vt)
+
+    def test_out_of_vt_uix_range(self):
+        MIN_VT_I8 = -(2**63)
+        MAX_VT_UI8 = 2**64 - 1
+        for val in [MIN_VT_I8 - 1, MAX_VT_UI8 + 1]:
+            with self.subTest(val=val), self.assertRaises(TypeError):
+                VARIANT().value = val
+
     def test_datetime(self):
         now = datetime.datetime.now()