diff --git a/gluon/contrib/redis_scheduler.py b/gluon/contrib/redis_scheduler.py
index 6a3f00fc..bc39201d 100644
--- a/gluon/contrib/redis_scheduler.py
+++ b/gluon/contrib/redis_scheduler.py
@@ -487,7 +487,7 @@ class RScheduler(Scheduler):
             # calc next_run_time based on available slots
             # see #1191
             next_run_time = task.start_time
-            secondspassed = self.total_seconds(now - next_run_time)
+            secondspassed = (now - next_run_time).total_seconds()
             steps = secondspassed // task.period + 1
             next_run_time += datetime.timedelta(seconds=task.period * steps)
 
diff --git a/gluon/tests/test_validators.py b/gluon/tests/test_validators.py
index 73712664..8afccc5a 100644
--- a/gluon/tests/test_validators.py
+++ b/gluon/tests/test_validators.py
@@ -977,6 +977,8 @@ class TestValidators(unittest.TestCase):
         self.assertEqual(rtn, (img, 'oops'))
         rtn = IS_IMAGE(error_message='oops', minsize=(100, 50))(img)
         self.assertEqual(rtn, (img, 'oops'))
+        rtn = IS_IMAGE(error_message='oops', aspectratio=(1, 1))(img)
+        self.assertEqual(rtn, (img, 'oops'))
 
         img = DummyImageFile('test', 'gif', 50, 100)
         rtn = IS_IMAGE()(img)
@@ -985,6 +987,8 @@ class TestValidators(unittest.TestCase):
         self.assertEqual(rtn, (img, 'oops'))
         rtn = IS_IMAGE(error_message='oops', minsize=(100, 50))(img)
         self.assertEqual(rtn, (img, 'oops'))
+        rtn = IS_IMAGE(error_message='oops', aspectratio=(1, 1))(img)
+        self.assertEqual(rtn, (img, 'oops'))
 
         img = DummyImageFile('test', 'jpeg', 50, 100)
         rtn = IS_IMAGE()(img)
@@ -993,6 +997,8 @@ class TestValidators(unittest.TestCase):
         self.assertEqual(rtn, (img, 'oops'))
         rtn = IS_IMAGE(error_message='oops', minsize=(100, 50))(img)
         self.assertEqual(rtn, (img, 'oops'))
+        rtn = IS_IMAGE(error_message='oops', aspectratio=(1, 1))(img)
+        self.assertEqual(rtn, (img, 'oops'))
 
         img = DummyImageFile('test', 'png', 50, 100)
         rtn = IS_IMAGE()(img)
@@ -1001,6 +1007,8 @@ class TestValidators(unittest.TestCase):
         self.assertEqual(rtn, (img, 'oops'))
         rtn = IS_IMAGE(error_message='oops', minsize=(100, 50))(img)
         self.assertEqual(rtn, (img, 'oops'))
+        rtn = IS_IMAGE(error_message='oops', aspectratio=(1, 1))(img)
+        self.assertEqual(rtn, (img, 'oops'))
 
         img = DummyImageFile('test', 'xls', 50, 100)
         rtn = IS_IMAGE(error_message='oops')(img)
diff --git a/gluon/validators.py b/gluon/validators.py
index 7e47f79c..541dddd1 100644
--- a/gluon/validators.py
+++ b/gluon/validators.py
@@ -3230,8 +3230,10 @@ class IS_IMAGE(Validator):
         ('jpg' extension of uploaded file counts as 'jpeg')
         maxsize: iterable containing maximum width and height of the image
         minsize: iterable containing minimum width and height of the image
+        aspectratio: iterable containing target aspect ratio
 
     Use (-1, -1) as minsize to pass image size check.
+    Use (-1, -1) as aspectratio to pass aspect ratio check.
 
     Examples:
         Check if uploaded file is in any of supported image formats:
@@ -3247,17 +3249,24 @@ class IS_IMAGE(Validator):
 
             INPUT(_type='file', _name='name',
                 requires=IS_IMAGE(extensions=('png'), maxsize=(200, 200)))
+
+        Check if uploaded file has a 16:9 aspect ratio:
+
+            INPUT(_type='file', _name='name',
+                requires=IS_IMAGE(aspectratio=(16, 9)))
     """
 
     def __init__(self,
                  extensions=('bmp', 'gif', 'jpeg', 'png'),
                  maxsize=(10000, 10000),
                  minsize=(0, 0),
+                 aspectratio=(-1, -1),
                  error_message='Invalid image'):
 
         self.extensions = extensions
         self.maxsize = maxsize
         self.minsize = minsize
+        self.aspectratio = aspectratio
         self.error_message = error_message
 
     def __call__(self, value):
@@ -3279,8 +3288,16 @@ class IS_IMAGE(Validator):
             else:
                 width = -1
                 height = -1
+
             assert self.minsize[0] <= width <= self.maxsize[0] \
                 and self.minsize[1] <= height <= self.maxsize[1]
+
+            if self.aspectratio > (-1, -1):
+                target_ratio = (1.0 * self.aspectratio[1]) / self.aspectratio[0]
+                actual_ratio = (1.0 * height) / width
+
+                assert actual_ratio == target_ratio
+
             value.file.seek(0)
             return (value, None)
         except Exception as e: