diff --git a/tools/patman/command.py b/tools/patman/command.py
index d1f0ca5..bebc495 100644
--- a/tools/patman/command.py
+++ b/tools/patman/command.py
@@ -85,7 +85,7 @@
 
         try:
             last_pipe = cros_subprocess.Popen(cmd, cwd=cwd, **kwargs)
-        except Exception, err:
+        except Exception as err:
             result.exception = err
             if raise_on_error:
                 raise Exception("Error running '%s': %s" % (user_pipestr, str))
diff --git a/tools/patman/cros_subprocess.py b/tools/patman/cros_subprocess.py
index 0fc4a06..ebd4300 100644
--- a/tools/patman/cros_subprocess.py
+++ b/tools/patman/cros_subprocess.py
@@ -166,7 +166,7 @@
         while read_set or write_set:
             try:
                 rlist, wlist, _ = select.select(read_set, write_set, [], 0.2)
-            except select.error, e:
+            except select.error as e:
                 if e.args[0] == errno.EINTR:
                     continue
                 raise
diff --git a/tools/patman/gitutil.py b/tools/patman/gitutil.py
index c0fe093..0d23079 100644
--- a/tools/patman/gitutil.py
+++ b/tools/patman/gitutil.py
@@ -139,7 +139,7 @@
         leaf = merge.split('/')[-1]
         return '%s/%s' % (remote, leaf), None
     else:
-        raise ValueError, ("Cannot determine upstream branch for branch "
+        raise ValueError("Cannot determine upstream branch for branch "
                 "'%s' remote='%s', merge='%s'" % (branch, remote, merge))
 
 
@@ -224,7 +224,7 @@
     result = command.RunPipe([pipe], capture=True, raise_on_error=False,
                              capture_stderr=True)
     if result.return_code != 0:
-        raise OSError, 'git checkout (%s): %s' % (pipe, result.stderr)
+        raise OSError('git checkout (%s): %s' % (pipe, result.stderr))
 
 def Clone(git_dir, output_dir):
     """Checkout the selected commit for this build
@@ -236,7 +236,7 @@
     result = command.RunPipe([pipe], capture=True, cwd=output_dir,
                              capture_stderr=True)
     if result.return_code != 0:
-        raise OSError, 'git clone: %s' % result.stderr
+        raise OSError('git clone: %s' % result.stderr)
 
 def Fetch(git_dir=None, work_tree=None):
     """Fetch from the origin repo
@@ -252,7 +252,7 @@
     pipe.append('fetch')
     result = command.RunPipe([pipe], capture=True, capture_stderr=True)
     if result.return_code != 0:
-        raise OSError, 'git fetch: %s' % result.stderr
+        raise OSError('git fetch: %s' % result.stderr)
 
 def CreatePatches(start, count, series):
     """Create a series of patches from the top of the current branch.
@@ -489,7 +489,7 @@
     if level > 10:
         msg = "Recursive email alias at '%s'" % lookup_name
         if raise_on_error:
-            raise OSError, msg
+            raise OSError(msg)
         else:
             print(col.Color(col.RED, msg))
             return out_list
@@ -498,7 +498,7 @@
         if not lookup_name in alias:
             msg = "Alias '%s' not found" % lookup_name
             if raise_on_error:
-                raise ValueError, msg
+                raise ValueError(msg)
             else:
                 print(col.Color(col.RED, msg))
                 return out_list