diff --git a/pycallgraph/config.py b/pycallgraph/config.py
index 5911fef..e3492c1 100755
--- a/pycallgraph/config.py
+++ b/pycallgraph/config.py
@@ -34,7 +34,7 @@ class Config(object):
         self.did_init = True
 
         # Update the defaults with anything from kwargs
-        [setattr(self, k, v) for k, v in kwargs.iteritems()]
+        [setattr(self, k, v) for k, v in kwargs.items()]
 
         self.create_parser()
 
diff --git a/pycallgraph/output/graphviz.py b/pycallgraph/output/graphviz.py
index 6f10049..d130d65 100644
--- a/pycallgraph/output/graphviz.py
+++ b/pycallgraph/output/graphviz.py
@@ -148,7 +148,7 @@ class GraphvizOutput(Output):
 
     def attrs_from_dict(self, d):
         output = []
-        for attr, val in d.iteritems():
+        for attr, val in d.items():
             output.append('%s = "%s"' % (attr, val))
         return ', '.join(output)
 
@@ -164,7 +164,7 @@ class GraphvizOutput(Output):
 
     def generate_attributes(self):
         output = []
-        for section, attrs in self.graph_attributes.iteritems():
+        for section, attrs in self.graph_attributes.items():
             output.append('{} [ {} ];'.format(
                 section, self.attrs_from_dict(attrs),
             ))
diff --git a/pycallgraph/output/output.py b/pycallgraph/output/output.py
index 9660d58..48eef49 100644
--- a/pycallgraph/output/output.py
+++ b/pycallgraph/output/output.py
@@ -16,14 +16,14 @@ class Output(object):
         self.edge_label_func = self.edge_label
 
         # Update the defaults with anything from kwargs
-        [setattr(self, k, v) for k, v in kwargs.iteritems()]
+        [setattr(self, k, v) for k, v in kwargs.items()]
 
     def set_config(self, config):
         '''
         This is a quick hack to move the config variables set in Config into
         the output module config variables.
         '''
-        for k, v in config.__dict__.iteritems():
+        for k, v in config.__dict__.items():
             if hasattr(self, k) and callable(getattr(self, k)):
                 continue
             setattr(self, k, v)
diff --git a/pycallgraph/tracer.py b/pycallgraph/tracer.py
index 17e9286..74a1477 100644
--- a/pycallgraph/tracer.py
+++ b/pycallgraph/tracer.py
@@ -297,7 +297,7 @@ class TraceProcessor(Thread):
         grp = defaultdict(list)
         for node in self.nodes():
             grp[self.group(node.name)].append(node)
-        for g in grp.iteritems():
+        for g in grp.items():
             yield g
 
     def stat_group_from_func(self, func, calls):
@@ -315,14 +315,14 @@ class TraceProcessor(Thread):
         return stat_group
 
     def nodes(self):
-        for func, calls in self.func_count.iteritems():
+        for func, calls in self.func_count.items():
             yield self.stat_group_from_func(func, calls)
 
     def edges(self):
-        for src_func, dests in self.call_dict.iteritems():
+        for src_func, dests in self.call_dict.items():
             if not src_func:
                 continue
-            for dst_func, calls in dests.iteritems():
+            for dst_func, calls in dests.items():
                 edge = self.stat_group_from_func(dst_func, calls)
                 edge.src_func = src_func
                 edge.dst_func = dst_func