diff --git a/Lib/lib2to3/pgen2/conv.py b/Lib/lib2to3/pgen2/conv.py
index bf49762..ed0cac5 100644
--- a/Lib/lib2to3/pgen2/conv.py
+++ b/Lib/lib2to3/pgen2/conv.py
@@ -60,7 +60,7 @@
         """
         try:
             f = open(filename)
-        except IOError as err:
+        except OSError as err:
             print("Can't open %s: %s" % (filename, err))
             return False
         self.symbol2number = {}
@@ -111,7 +111,7 @@
         """
         try:
             f = open(filename)
-        except IOError as err:
+        except OSError as err:
             print("Can't open %s: %s" % (filename, err))
             return False
         # The code below essentially uses f's iterator-ness!
diff --git a/Lib/lib2to3/pgen2/driver.py b/Lib/lib2to3/pgen2/driver.py
index 4c611c6..3ccc69d 100644
--- a/Lib/lib2to3/pgen2/driver.py
+++ b/Lib/lib2to3/pgen2/driver.py
@@ -123,7 +123,7 @@
             logger.info("Writing grammar tables to %s", gp)
             try:
                 g.dump(gp)
-            except IOError as e:
+            except OSError as e:
                 logger.info("Writing failed:"+str(e))
     else:
         g = grammar.Grammar()
diff --git a/Lib/lib2to3/refactor.py b/Lib/lib2to3/refactor.py
index 87f686e..8100317 100644
--- a/Lib/lib2to3/refactor.py
+++ b/Lib/lib2to3/refactor.py
@@ -326,7 +326,7 @@
         """
         try:
             f = open(filename, "rb")
-        except IOError as err:
+        except OSError as err:
             self.log_error("Can't open %s: %s", filename, err)
             return None, None
         try: