diff --git a/src/sage/combinat/designs/ext_rep.py b/src/sage/combinat/designs/ext_rep.py
index 60d6c7ea688..8b625fbe825 100644
--- a/src/sage/combinat/designs/ext_rep.py
+++ b/src/sage/combinat/designs/ext_rep.py
@@ -736,7 +736,7 @@ def __getitem__(self, i):
         try:
             child = self.xt_children[i]
         except IndexError:
-            raise IndexError, '%s no index %s' % (self.__repr__(), `i`)
+            raise IndexError, '%s no index %s' % (self.__repr__(), repr(i))
         if type(child) == TupleType:
             name, attributes, children = child
             if len(attributes) > 0:
diff --git a/src/sage/combinat/ncsf_qsym/ncsf.py b/src/sage/combinat/ncsf_qsym/ncsf.py
index 8a48f910d88..7642ee9fecc 100644
--- a/src/sage/combinat/ncsf_qsym/ncsf.py
+++ b/src/sage/combinat/ncsf_qsym/ncsf.py
@@ -1376,7 +1376,7 @@ def coproduct_on_generators(self, i):
                     'Not a positive integer: 0'
                 """
                 if i<1:
-                    return "Not a positive integer: %s" % `i`
+                    return "Not a positive integer: %s" % repr(i)
                 def C(i): return self._basis_keys([i]) if i else self._basis_keys([])
                 T = self.tensor_square()
                 return T.sum_of_monomials( (C(j), C(i-j)) for j in range(0,i+1) )
@@ -1462,7 +1462,7 @@ def antipode_on_generators(self, i):
                     'Not a positive integer: 0'
                 """
                 if i<1:
-                    return "Not a positive integer: %s" % `i`
+                    return "Not a positive integer: %s" % repr(i)
                 return - self.algebra_generators()[i]
 
             def coproduct_on_generators(self, i):
@@ -1488,7 +1488,7 @@ def coproduct_on_generators(self, i):
                     'Not a positive integer: 0'
                 """
                 if i<1:
-                    return "Not a positive integer: %s" % `i`
+                    return "Not a positive integer: %s" % repr(i)
                 x = self.algebra_generators()[i]
                 from sage.categories.all import tensor
                 return tensor([self.one(), x]) + tensor([x, self.one()])
diff --git a/src/sage/interfaces/frobby.py b/src/sage/interfaces/frobby.py
index 06991495315..106e28c01d8 100644
--- a/src/sage/interfaces/frobby.py
+++ b/src/sage/interfaces/frobby.py
@@ -61,8 +61,8 @@ def __call__(self, action, input=None, options=[], verbose=False):
 
         if verbose:
             print "Frobby action: ", action
-            print "Frobby options: ", `options`
-            print "Frobby command: ", `command`
+            print "Frobby options: ", repr(options)
+            print "Frobby command: ", repr(command)
             print "Frobby input:\n", input
 
         process = Popen(command, stdin = PIPE, stdout = PIPE, stderr = PIPE)
diff --git a/src/sage/modular/quatalg/brandt.py b/src/sage/modular/quatalg/brandt.py
index 5db911aba1c..024631608e2 100644
--- a/src/sage/modular/quatalg/brandt.py
+++ b/src/sage/modular/quatalg/brandt.py
@@ -1194,7 +1194,7 @@ def _ideal_products(self):
         L = self.right_ideals()
         n = len(L)
         if n == 0:
-            return matrix(self.base_ring()[[`q`]],0)
+            return matrix(self.base_ring()[[repr(q)]],0)
 
         # 1. Compute the theta series
         P = []