diff --git a/pytimeparse/tests/testtimeparse.py b/pytimeparse/tests/testtimeparse.py
index c305bb5..9022e3b 100644
--- a/pytimeparse/tests/testtimeparse.py
+++ b/pytimeparse/tests/testtimeparse.py
@@ -358,6 +358,18 @@ def test_timeparse_33(self):
         self.assertEqual(timeparse.timeparse('+5.6 weeks'), 3386880)
         self.assertEqual(timeparse.timeparse('-5.6 weeks'), -3386880)
 
+    def test_out_of_range(self):
+        '''An absurdly large value returns None instead of raising.'''
+        # The number is syntactically valid but so large that float()
+        # overflows to inf, which int() cannot convert. That used to leak
+        # an OverflowError; it should be treated as unparseable (None), the
+        # same as any other malformed number.
+        for value in ('9' * 400 + '.5 minutes',
+                      '1' * 350 + '.1 hours',
+                      '5' * 500 + '.5 days',
+                      '9' * 400 + '.9 wk'):
+            self.assertIsNone(timeparse.timeparse(value))
+
     def test_doctest(self):
         '''Run timeparse doctests.'''
         self.assertTrue(doctest.testmod(timeparse, raise_on_error=True))
diff --git a/pytimeparse/timeparse.py b/pytimeparse/timeparse.py
index ace5cc3..8d83725 100644
--- a/pytimeparse/timeparse.py
+++ b/pytimeparse/timeparse.py
@@ -181,7 +181,11 @@ def timeparse(sval, granularity='seconds'):
                     # SECS is a float, we will return a float
                     return sign * sum([MULTIPLIERS[k] * float(v) for (k, v) in
                                 list(mdict.items()) if v is not None])
-            except ValueError:
-                # Malformed number string (e.g. '1.2.3', '.') — skip to
-                # the next time format pattern per documented behavior.
+            except (ValueError, OverflowError):
+                # A malformed number string (e.g. '1.2.3', '.') raises
+                # ValueError, and an absurdly large value whose float()
+                # overflows to inf (so int() cannot convert it) raises
+                # OverflowError. In either case the field is not a usable
+                # number, so skip to the next time format pattern, per the
+                # documented behavior of returning None for unparseable input.
                 pass