diff --git a/redo/builder.py b/redo/builder.py
index 414aaa7..c07cd47 100644
--- a/redo/builder.py
+++ b/redo/builder.py
@@ -11,7 +11,7 @@ def _nice(t):
 def _try_stat(filename):
     try:
         return os.lstat(filename)
-    except OSError, e:
+    except OSError as e:
         if e.errno == errno.ENOENT:
             return None
         else:
@@ -90,7 +90,7 @@ def start_stdin_log_reader(status, details, pretty, color,
                 argv.append('--color' if color >= 2 else '--no-color')
             argv.append('-')
             os.execvp(argv[0], argv)
-        except Exception, e:  # pylint: disable=broad-except
+        except Exception as e:  # pylint: disable=broad-except
             sys.stderr.write('redo-log: exec: %s\n' % e)
         finally:
             os._exit(99)
@@ -138,7 +138,7 @@ class _BuildJob(object):
                 if is_target:
                     meta('unchanged', state.target_relpath(self.t))
                 return self._finalize(0)
-        except helpers.ImmediateReturn, e:
+        except helpers.ImmediateReturn as e:
             return self._finalize(e.rv)
 
         if env.v.NO_OOB or dirty == True:  # pylint: disable=singleton-comparison
@@ -398,7 +398,7 @@ class _BuildJob(object):
                 helpers.unlink(self.tmpname)
                 try:
                     newf = open(self.tmpname, 'w')
-                except IOError, e:
+                except IOError as e:
                     dnt = os.path.dirname(os.path.abspath(t))
                     if not os.path.exists(dnt):
                         # This could happen, so report a simple error message
@@ -424,7 +424,7 @@ class _BuildJob(object):
                 try:
                     # Atomically replace the target file
                     os.rename(self.tmpname, t)
-                except OSError, e:
+                except OSError as e:
                     # This could happen for, eg. a permissions error on
                     # the target directory.
                     err('%s: rename %s: %s\n' % (t, self.tmpname, e))
diff --git a/redo/cmd_ifchange.py b/redo/cmd_ifchange.py
index aaa0e41..bf593a5 100644
--- a/redo/cmd_ifchange.py
+++ b/redo/cmd_ifchange.py
@@ -52,7 +52,7 @@ def main():
             finally:
                 try:
                     jobserver.force_return_tokens()
-                except Exception, e:  # pylint: disable=broad-except
+                except Exception as e:  # pylint: disable=broad-except
                     traceback.print_exc(100, sys.stderr)
                     err('unexpected error: %r\n' % e)
                     rv = 1
diff --git a/redo/cmd_log.py b/redo/cmd_log.py
index 7d666b9..c4ae48c 100644
--- a/redo/cmd_log.py
+++ b/redo/cmd_log.py
@@ -102,7 +102,7 @@ def catlog(t):
         if not f:
             try:
                 f = open(logname)
-            except IOError, e:
+            except IOError as e:
                 if e.errno == errno.ENOENT:
                     # ignore files without logs
                     pass
@@ -231,7 +231,7 @@ def catlog(t):
         status = None
     if line_head:
         # partial line never got terminated
-        print line_head
+        print(line_head)
     if t != '-':
         assert depth[-1] == t
         depth.pop(-1)
@@ -274,7 +274,7 @@ def main():
             catlog(t)
     except KeyboardInterrupt:
         sys.exit(200)
-    except IOError, e:
+    except IOError as e:
         if e.errno == errno.EPIPE:
             pass
         else:
diff --git a/redo/cmd_ood.py b/redo/cmd_ood.py
index ece5441..a225034 100644
--- a/redo/cmd_ood.py
+++ b/redo/cmd_ood.py
@@ -36,7 +36,7 @@ def main():
                             is_checked=is_checked,
                             set_checked=set_checked,
                             log_override=log_override):
-                print state.relpath(os.path.join(env.v.BASE, f.name), cwd)
+                print(state.relpath(os.path.join(env.v.BASE, f.name), cwd))
 
 
 if __name__ == '__main__':
diff --git a/redo/cmd_redo.py b/redo/cmd_redo.py
index 15f5f64..8790a45 100644
--- a/redo/cmd_redo.py
+++ b/redo/cmd_redo.py
@@ -48,7 +48,7 @@ def main():
 
     if opt.version:
         from . import version
-        print version.TAG
+        print(version.TAG)
         sys.exit(0)
     if opt.debug:
         os.environ['REDO_DEBUG'] = str(opt.debug or 0)
@@ -114,7 +114,7 @@ def main():
             finally:
                 try:
                     jobserver.force_return_tokens()
-                except Exception, e:  # pylint: disable=broad-except
+                except Exception as e:  # pylint: disable=broad-except
                     traceback.print_exc(100, sys.stderr)
                     err('unexpected error: %r\n' % e)
                     retcode = 1
diff --git a/redo/cmd_sources.py b/redo/cmd_sources.py
index 2229452..0e1326a 100644
--- a/redo/cmd_sources.py
+++ b/redo/cmd_sources.py
@@ -16,7 +16,7 @@ def main():
     cwd = os.getcwd()
     for f in state.files():
         if f.is_source():
-            print state.relpath(os.path.join(env.v.BASE, f.name), cwd)
+            print(state.relpath(os.path.join(env.v.BASE, f.name), cwd))
 
 
 if __name__ == '__main__':
diff --git a/redo/cmd_targets.py b/redo/cmd_targets.py
index 1a73dc5..c1876a4 100644
--- a/redo/cmd_targets.py
+++ b/redo/cmd_targets.py
@@ -16,7 +16,7 @@ def main():
     cwd = os.getcwd()
     for f in state.files():
         if f.is_target():
-            print state.relpath(os.path.join(env.v.BASE, f.name), cwd)
+            print(state.relpath(os.path.join(env.v.BASE, f.name), cwd))
 
 
 if __name__ == '__main__':
diff --git a/redo/cmd_whichdo.py b/redo/cmd_whichdo.py
index 170ebe6..e926de9 100644
--- a/redo/cmd_whichdo.py
+++ b/redo/cmd_whichdo.py
@@ -26,7 +26,7 @@ def main():
         relpath = os.path.relpath(dopath, '.')
         exists = os.path.exists(dopath)
         assert '\n' not in relpath
-        print relpath
+        print(relpath)
         if exists:
             sys.exit(0)
     sys.exit(1)   # no appropriate dofile found
diff --git a/redo/helpers.py b/redo/helpers.py
index 55d190c..d59e519 100644
--- a/redo/helpers.py
+++ b/redo/helpers.py
@@ -16,7 +16,7 @@ def unlink(f):
     """
     try:
         os.unlink(f)
-    except OSError, e:
+    except OSError as e:
         if e.errno == errno.ENOENT:
             pass  # it doesn't exist, that's what you asked for
 
diff --git a/redo/jobserver.py b/redo/jobserver.py
index ab6984f..acd3f4f 100644
--- a/redo/jobserver.py
+++ b/redo/jobserver.py
@@ -98,7 +98,7 @@ def _create_tokens(n):
     global _mytokens, _cheats
     assert n >= 0
     assert _cheats >= 0
-    for _ in xrange(n):
+    for _ in range(n):
         if _cheats > 0:
             _cheats -= 1
         else:
@@ -118,7 +118,7 @@ def _release(n):
     assert _mytokens >= n
     _debug('%d,%d -> release(%d)\n' % (_mytokens, _cheats, n))
     n_to_share = 0
-    for _ in xrange(n):
+    for _ in range(n):
         _mytokens -= 1
         if _cheats > 0:
             _cheats -= 1
@@ -176,7 +176,7 @@ def _try_read(fd, n):
         signal.setitimer(signal.ITIMER_REAL, 0.01, 0.01)  # emergency fallback
         try:
             b = os.read(fd, 1)
-        except OSError, e:
+        except OSError as e:
             if e.errno in (errno.EAGAIN, errno.EINTR):
                 # interrupted or it was nonblocking
                 return None  # try again
@@ -297,7 +297,7 @@ def _wait(want_token, max_delay):
     Returns:
       None
     """
-    rfds = _waitfds.keys()
+    rfds = list(_waitfds.keys())
     if want_token:
         rfds.append(_tokenfds[0])
     assert rfds
diff --git a/redo/options.py b/redo/options.py
index 1bada98..9be69e5 100644
--- a/redo/options.py
+++ b/redo/options.py
@@ -239,12 +239,12 @@ class Options:
         """
         try:
             (flags,extra) = self.optfunc(args, self._shortopts, self._longopts)
-        except getopt.GetoptError, e:
+        except getopt.GetoptError as e:
             self.fatal(e)
 
         opt = OptDict()
 
-        for k,v in self._defaults.iteritems():
+        for k,v in self._defaults.items():
             k = self._aliases[k]
             opt[k] = v
 
@@ -268,6 +268,6 @@ class Options:
                 else:
                     v = _intify(v)
             opt[k] = v
-        for (f1,f2) in self._aliases.iteritems():
+        for (f1,f2) in self._aliases.items():
             opt[f1] = opt._opts.get(f2)
         return (opt,flags,extra)
diff --git a/redo/state.py b/redo/state.py
index 4ad5f53..37b1856 100644
--- a/redo/state.py
+++ b/redo/state.py
@@ -46,14 +46,14 @@ def db():
     dbfile = '%s/db.sqlite3' % dbdir
     try:
         os.mkdir(dbdir)
-    except OSError, e:
+    except OSError as e:
         if e.errno == errno.EEXIST:
             pass  # if it exists, that's okay
         else:
             raise
 
     _lockfile = os.open(os.path.join(env.v.BASE, '.redo/locks'),
-                        os.O_RDWR | os.O_CREAT, 0666)
+                        os.O_RDWR | os.O_CREAT, 0o666)
     close_on_exec(_lockfile, True)
     if env.is_toplevel and detect_broken_locks():
         env.mark_locks_broken()
@@ -508,7 +508,7 @@ class Lock(object):
         assert not self.owned
         try:
             fcntl.lockf(_lockfile, fcntl.LOCK_EX|fcntl.LOCK_NB, 1, self.fid)
-        except IOError, e:
+        except IOError as e:
             if e.errno in (errno.EAGAIN, errno.EACCES):
                 pass  # someone else has it locked
             else: