diff --git a/TODO b/TODO
index 95787836..710b2429 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,16 @@
 
 - python:
 
+	- try:
+
+		$ python test_arithmetic.py -v TestArithmetic.test_moreeq
+		test_moreeq (__main__.TestArithmetic) ... **
+		VIPS:ERROR:cache.c:606:vips_cache_insert: assertion failed:
+		(!g_hash_table_lookup( vips_cache_table, operation ))
+		Aborted (core dumped)
+
+	  same for more; less, lesseq, equal and noteq are fine
+
 	- could import like this:
 
 		from gi.repository import Vips 
diff --git a/python/test_arithmetic.py b/python/test_arithmetic.py
index ee480922..22f257e0 100755
--- a/python/test_arithmetic.py
+++ b/python/test_arithmetic.py
@@ -56,8 +56,8 @@ def run_fn2(fn, x, y):
 class TestArithmetic(unittest.TestCase):
     # test a pair of things which can be lists for approx. equality
     def assertAlmostEqualObjects(self, a, b, msg = ''):
+        #print 'assertAlmostEqualObjects %s = %s' % (a, b)
         for x, y in zip_expand(a, b):
-            #print 'assertAlmostEqual %s = %s' % (x, y)
             self.assertAlmostEqual(x, y, places = 4, msg = msg)
 
     # run a function on an image and on a single pixel, the results 
@@ -195,6 +195,84 @@ class TestArithmetic(unittest.TestCase):
         self.run_arith_const(my_xor, fmt = noncomplex_formats)
         self.run_arith(my_xor, fmt = noncomplex_formats)
 
+    def test_more(self):
+        def more(x, y):
+            if isinstance(x, Vips.Image) or isinstance(y, Vips.Image):
+                return x > y
+            else:
+                if x > y:
+                    return 255
+                else:
+                    return 0
+
+        self.run_arith_const(more)
+        self.run_arith(more)
+
+    def test_moreeq(self):
+        def moreeq(x, y):
+            if isinstance(x, Vips.Image) or isinstance(y, Vips.Image):
+                return x >= y
+            else:
+                if x >= y:
+                    return 255
+                else:
+                    return 0
+
+        self.run_arith_const(moreeq)
+        self.run_arith(moreeq)
+
+    def test_less(self):
+        def less(x, y):
+            if isinstance(x, Vips.Image) or isinstance(y, Vips.Image):
+                return x < y
+            else:
+                if x < y:
+                    return 255
+                else:
+                    return 0
+
+        self.run_arith_const(less)
+        self.run_arith(less)
+
+    def test_lesseq(self):
+        def lesseq(x, y):
+            if isinstance(x, Vips.Image) or isinstance(y, Vips.Image):
+                return x <= y
+            else:
+                if x <= y:
+                    return 255
+                else:
+                    return 0
+
+        self.run_arith_const(lesseq)
+        self.run_arith(lesseq)
+
+    def test_equal(self):
+        def equal(x, y):
+            if isinstance(x, Vips.Image) or isinstance(y, Vips.Image):
+                return x == y
+            else:
+                if x == y:
+                    return 255
+                else:
+                    return 0
+
+        self.run_arith_const(equal)
+        self.run_arith(equal)
+
+    def test_noteq(self):
+        def noteq(x, y):
+            if isinstance(x, Vips.Image) or isinstance(y, Vips.Image):
+                return x != y
+            else:
+                if x != y:
+                    return 255
+                else:
+                    return 0
+
+        self.run_arith_const(noteq)
+        self.run_arith(noteq)
+
     # run a function on an image, 
     # 50,50 and 10,10 should have different values on the test image
     def run_testunary(self, message, im, fn):
diff --git a/python/vips8/vips.py b/python/vips8/vips.py
index f0068caf..6cb99a82 100644
--- a/python/vips8/vips.py
+++ b/python/vips8/vips.py
@@ -422,37 +422,37 @@ def vips_more(self, other):
     if isinstance(other, Vips.Image):
         return self.relational(other, Vips.OperationRelational.MORE)
     else:
-        return self.relational_const(Vips.OperationRelational.MORE, other)
+        return self.relational_const(other, Vips.OperationRelational.MORE)
 
 def vips_moreeq(self, other):
     if isinstance(other, Vips.Image):
         return self.relational(other, Vips.OperationRelational.MOREEQ)
     else:
-        return self.relational_const(Vips.OperationRelational.MOREEQ, other)
+        return self.relational_const(other, Vips.OperationRelational.MOREEQ)
 
 def vips_less(self, other):
     if isinstance(other, Vips.Image):
-        return self.relational(other, Vips.OperationRelational.MORE)
+        return self.relational(other, Vips.OperationRelational.LESS)
     else:
-        return self.relational_const(Vips.OperationRelational.MORE, other)
+        return self.relational_const(other, Vips.OperationRelational.LESS)
 
 def vips_lesseq(self, other):
     if isinstance(other, Vips.Image):
         return self.relational(other, Vips.OperationRelational.LESSEQ)
     else:
-        return self.relational_const(Vips.OperationRelational.LESSEQ, other)
+        return self.relational_const(other, Vips.OperationRelational.LESSEQ)
 
 def vips_equal(self, other):
     if isinstance(other, Vips.Image):
         return self.relational(other, Vips.OperationRelational.EQUAL)
     else:
-        return self.relational_const(Vips.OperationRelational.EQUAL, other)
+        return self.relational_const(other, Vips.OperationRelational.EQUAL)
 
 def vips_notequal(self, other):
     if isinstance(other, Vips.Image):
         return self.relational(other, Vips.OperationRelational.NOTEQ)
     else:
-        return self.relational_const(Vips.OperationRelational.NOTEQ, other)
+        return self.relational_const(other, Vips.OperationRelational.NOTEQ)
 
 def vips_neg(self):
     return -1 * self