diff --git a/mmgen/altcoins/eth/obj.py b/mmgen/altcoins/eth/obj.py
index 49afb9ac..fc638c17 100755
--- a/mmgen/altcoins/eth/obj.py
+++ b/mmgen/altcoins/eth/obj.py
@@ -20,10 +20,10 @@
 altcoins.eth.obj: Ethereum data type classes for the MMGen suite
 """
 
-# Kwei (babbage) 3, Mwei (lovelace) 6, Gwei (shannon) 9, µETH (szabo) 12, mETH (finney) 15, ETH 18
 from decimal import Decimal
-from mmgen.color import *
-from mmgen.obj import *
+from mmgen.obj import BTCAmt,Int
+
+# Kwei (babbage) 3, Mwei (lovelace) 6, Gwei (shannon) 9, µETH (szabo) 12, mETH (finney) 15, ETH 18
 class ETHAmt(BTCAmt):
 	max_prec = 18
 	max_amt = None
@@ -44,20 +44,5 @@ class ETHAmt(BTCAmt):
 	def toSzabo(self):  return int(Decimal(self) // self.szabo)
 	def toFinney(self): return int(Decimal(self) // self.finney)
 
-class ETHNonce(int,Hilite,InitErrors): # WIP
-	def __new__(cls,n,on_fail='die'):
-		if type(n) == cls: return n
-		cls.arg_chk(on_fail)
-		from mmgen.util import is_int
-		try:
-			assert is_int(n),"'{}': value is not an integer".format(n)
-			n = int(n)
-			assert n >= 0,"'{}': value is negative".format(n)
-			return int.__new__(cls,n)
-		except Exception as e:
-			return cls.init_fail(e,n)
-
-	@classmethod
-	def colorize(cls,s,color=True):
-		k = color if type(color) is str else cls.color # hack: override color with str value
-		return globals()[k](str(s)) if (color or cls.color_always) else str(s)
+class ETHNonce(Int):
+	min_val = 0
diff --git a/mmgen/obj.py b/mmgen/obj.py
index 48b388bf..c96cf9d0 100755
--- a/mmgen/obj.py
+++ b/mmgen/obj.py
@@ -181,7 +181,32 @@ class Hilite(object):
 		return self.colorize(self,color=False)
 
 class Str(str,Hilite): pass
-class Int(int,Hilite): pass
+
+class Int(int,Hilite,InitErrors):
+	min_val = None
+	max_val = None
+	max_digits = None
+	color = 'red'
+
+	def __new__(cls,n,base=10,on_fail='raise'):
+		if type(n) == cls:
+			return n
+		cls.arg_chk(on_fail)
+		try:
+			me = int.__new__(cls,str(n),base)
+			if cls.min_val != None:
+				assert me >= cls.min_val,'is less than cls.min_val ({})'.format(cls.min_val)
+			if cls.max_val != None:
+				assert me <= cls.max_val,'is greater than cls.max_val ({})'.format(cls.max_val)
+			if cls.max_digits != None:
+				assert len(str(me)) <= cls.max_digits,'has more than {} digits'.format(cls.max_digits)
+			return me
+		except Exception as e:
+			return cls.init_fail(e,n)
+
+	@classmethod
+	def colorize(cls,n,color=True):
+		return Hilite.colorize(repr(n),color=color)
 
 # For attrs that are always present in the data instance
 # Reassignment and deletion forbidden
@@ -285,24 +310,7 @@ class MMGenListItem(MMGenObject):
 			raise AttributeError(m.format(name,type(self)))
 		return object.__setattr__(self,name,value)
 
-class MMGenIdx(int,InitErrors):
-	min_val = 1
-	max_val = None
-	max_digits = None
-	def __new__(cls,num,on_fail='die'):
-		cls.arg_chk(on_fail)
-		try:
-			assert type(num) is not float,'is float'
-			me = int.__new__(cls,num)
-			if cls.max_digits:
-				assert len(str(me)) <= cls.max_digits,'has more than {} digits'.format(cls.max_digits)
-			if cls.max_val:
-				assert me <= cls.max_val,'is greater than {}'.format(cls.max_val)
-			assert me >= cls.min_val,'is less than {}'.format(cls.min_val)
-			return me
-		except Exception as e:
-			return cls.init_fail(e,num)
-
+class MMGenIdx(Int): min_val = 1
 class SeedShareIdx(MMGenIdx): max_val = 1024
 class SeedShareCount(SeedShareIdx): min_val = 2
 class MasterShareIdx(MMGenIdx): max_val = 1024
diff --git a/test/objtest_py_d/ot_btc_mainnet.py b/test/objtest_py_d/ot_btc_mainnet.py
index bb7da71e..5515930d 100755
--- a/test/objtest_py_d/ot_btc_mainnet.py
+++ b/test/objtest_py_d/ot_btc_mainnet.py
@@ -16,6 +16,16 @@ from .ot_common import *
 ssm = str(SeedShareCount.max_val)
 
 tests = OrderedDict([
+	('Int', {
+		'bad':  ('1L',0.0,'0.0','1.0',1.0,'s',1.1,'1.1'),
+		'good': (
+			('0',0),('-1',-1),('7',7),-1,0,1,9999999,
+			{'n':'0x0','base':16,'ret':0},
+			{'n':'0x1','base':16,'ret':1},
+			{'n':'0xf','base':16,'ret':15},
+			{'n':'0xff','base':16,'ret':255},
+		)
+	}),
 	('AddrIdx', {
 		'bad':  ('s',1.1,10000000,-1,0),
 		'good': (('7',7),(1,1),(9999999,9999999))
diff --git a/test/objtest_py_d/ot_eth_mainnet.py b/test/objtest_py_d/ot_eth_mainnet.py
index afbe689f..b94dd49e 100755
--- a/test/objtest_py_d/ot_eth_mainnet.py
+++ b/test/objtest_py_d/ot_eth_mainnet.py
@@ -29,7 +29,13 @@ tests = OrderedDict([
 		)
 	}),
 	('ETHNonce', {
-		'bad': ('U','z','я',-1),
-		'good':  (('0',0),('1',1),('100',100),1,100)
+		'bad': ('z','я',-1,'-1',0.0,'0.0'),
+		'good': (
+			('0',0),('1',1),('100',100),1,100,
+			{'n':'0x0','base':16,'ret':0},
+			{'n':'0x1','base':16,'ret':1},
+			{'n':'0xf','base':16,'ret':15},
+			{'n':'0xff','base':16,'ret':255},
+		)
 	}),
 ])