diff --git a/problemtools/ProblemPlasTeX/ProblemsetMacros.py b/problemtools/ProblemPlasTeX/ProblemsetMacros.py
index fadd4a3b..1079d605 100644
--- a/problemtools/ProblemPlasTeX/ProblemsetMacros.py
+++ b/problemtools/ProblemPlasTeX/ProblemsetMacros.py
@@ -1,14 +1,21 @@
 import sys
 import os
 import os.path
-import codecs
-import cgi
+import io
 from plasTeX.DOM import Node
 from plasTeX.Base import Command
 from plasTeX.Base import DimenCommand
 from plasTeX.Logging import getLogger
 import plasTeX.Packages.graphics as graphics
 
+if sys.version_info.major == 2:
+    import cgi
+    def plastex_escape(s):
+        return cgi.escape(s)
+else:
+    def plastex_escape(s):
+        return s
+
 log = getLogger()
 status = getLogger('status')
 
@@ -46,8 +53,8 @@ class sampletable(Command):
     args = 'header1 file1:str header2 file2:str'
 
     def read_sample_file(self, filename):
-        data = open(filename, 'rb').read().decode('utf8')
-        data = cgi.escape(data)
+        data = io.open(filename, 'r', encoding='utf-8').read()
+        data = plastex_escape(data)
         return data
 
     def invoke(self, tex):
@@ -70,7 +77,7 @@ class sampletableinteractive(Command):
     args = 'header read write file:str'
 
     def read_sample_interaction(self, filename):
-        data = open(filename, 'rb').read().decode('utf8')
+        data = io.open(filename, 'r', encoding='utf-8').read()
         messages = []
         cur_msg = []
         cur_mode = None
@@ -82,12 +89,12 @@ def read_sample_interaction(self, filename):
             line = line[1:]
             if mode != cur_mode:
                 if cur_mode: messages.append({'mode': cur_mode,
-                                              'data': cgi.escape('\n'.join(cur_msg))})
+                                              'data': plastex_escape('\n'.join(cur_msg))})
                 cur_msg = []
             cur_msg.append(line)
             cur_mode = mode
         if cur_mode: messages.append({'mode': cur_mode,
-                                      'data': cgi.escape('\n'.join(cur_msg))})
+                                      'data': plastex_escape('\n'.join(cur_msg))})
         return messages
 
     def invoke(self, tex):
diff --git a/problemtools/ProblemPlasTeX/listingsutf8.py b/problemtools/ProblemPlasTeX/listingsutf8.py
index da3d4cee..2a2d1f56 100644
--- a/problemtools/ProblemPlasTeX/listingsutf8.py
+++ b/problemtools/ProblemPlasTeX/listingsutf8.py
@@ -1,8 +1,10 @@
 from plasTeX.Base import Command
 from plasTeX.Logging import getLogger
 
-import cgi
 import os
+import io
+
+import ProblemsetMacros
 
 log = getLogger()
 
@@ -13,8 +15,8 @@ class lstinputlisting(Command):
     args = '* [ options:dict ] file:str'
 
     def read_file(self, filename):
-        data = open(filename, 'r').read().decode('utf8')
-        data = cgi.escape(data)
+        data = io.open(filename, 'r', encoding='utf-8').read()
+        data = ProblemsetMacros.plastex_escape(data)
         return data
 
     def invoke(self, tex):
diff --git a/problemtools/verifyproblem.py b/problemtools/verifyproblem.py
index c3a8b3af..4be46423 100644
--- a/problemtools/verifyproblem.py
+++ b/problemtools/verifyproblem.py
@@ -300,7 +300,8 @@ def __init__(self, problem, datadir, parent=None):
         configfile = os.path.join(self._datadir, 'testdata.yaml')
         if os.path.isfile(configfile):
             try:
-                self.config = yaml.safe_load(file(configfile))
+                with open(configfile) as f:
+                    self.config = yaml.safe_load(f)
             except Exception as e:
                 self.error(e)
                 self.config = {}