diff --git a/bin/verilator_ccache_report b/bin/verilator_ccache_report
index f895db4ae..bbb69b9af 100755
--- a/bin/verilator_ccache_report
+++ b/bin/verilator_ccache_report
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0115,C0116,C0123,C0301,R0902,R0913,R0914,R0912,R0915,W0621
+# pylint: disable=C0103,C0114,C0115,C0116,C0123,C0209,C0301,R0902,R0913,R0914,R0912,R0915,W0621
 ######################################################################
 
 import argparse
diff --git a/bin/verilator_difftree b/bin/verilator_difftree
index d7c65a28e..2bede0e8d 100755
--- a/bin/verilator_difftree
+++ b/bin/verilator_difftree
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0116
+# pylint: disable=C0103,C0114,C0116,C0209
 ######################################################################
 
 import argparse
@@ -73,7 +73,7 @@ def diff_file(a, b):
 
 def version_from(filename):
     # Return dump format
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         lineno = 0
         for line in fh:
             if lineno > 10:
@@ -86,8 +86,8 @@ def version_from(filename):
 
 def filterf(fn1, fn2):
     # Remove hex numbers before diffing
-    with open(fn1) as fh1:
-        with open(fn2, "w") as fh2:
+    with open(fn1, "r", encoding="utf8") as fh1:
+        with open(fn2, "w", encoding="utf8") as fh2:
             for line in fh1:
                 if re.search(r' This=', line):
                     continue
diff --git a/bin/verilator_gantt b/bin/verilator_gantt
index 03a7a16af..cfab96456 100755
--- a/bin/verilator_gantt
+++ b/bin/verilator_gantt
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0116,C0301,R0914,R0912,R0915,W0511,eval-used
+# pylint: disable=C0103,C0114,C0116,C0209,C0301,R0914,R0912,R0915,W0511,eval-used
 ######################################################################
 
 import argparse
@@ -29,7 +29,7 @@ def process(filename):
 
 
 def read_data(filename):
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         re_thread = re.compile(r'^VLPROFTHREAD (\d+)$')
         re_record = re.compile(r'^VLPROFEXEC (\S+) (\d+)(.*)$')
         re_payload_mtaskBegin = re.compile(
@@ -318,7 +318,7 @@ def report_cpus():
 
 def write_vcd(filename):
     print("Writing %s" % filename)
-    with open(filename, "w") as fh:
+    with open(filename, "w", encoding="utf8") as fh:
         vcd = {
             'values':
             collections.defaultdict(lambda: {}),  # {<time>}{<code>} = value
diff --git a/bin/verilator_profcfunc b/bin/verilator_profcfunc
index 4f6b82442..abf1c06b8 100755
--- a/bin/verilator_profcfunc
+++ b/bin/verilator_profcfunc
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0116,R0914,R0912,R0915,eval-used
+# pylint: disable=C0103,C0114,C0116,C0209,R0914,R0912,R0915,eval-used
 ######################################################################
 
 import argparse
@@ -13,7 +13,7 @@ import re
 def profcfunc(filename):
     funcs = {}
 
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
 
         for line in fh:
             #                  %time      cumesec   selfsec     calls     {stuff}   name
@@ -67,16 +67,15 @@ def profcfunc(filename):
     groups['design'] = collections.defaultdict(lambda: 0)
     groups['module'] = collections.defaultdict(lambda: 0)
 
-    for func in funcs:
-        pct = funcs[func]['pct']
+    for func, func_item in funcs.items():
+        pct = func_item['pct']
         vfunc = func
 
         funcarg = re.sub(r'^.*\(', '', func)
 
         design = None
-        for vde in verilated_mods:
-            if verilated_mods[vde].match(func) or verilated_mods[vde].match(
-                    funcarg):
+        for vde, vde_item in verilated_mods.items():
+            if vde_item.match(func) or vde_item.match(funcarg):
                 design = vde
                 break
 
@@ -114,12 +113,12 @@ def profcfunc(filename):
             groups['module']['C++'] += pct
 
         if vfunc not in vfuncs:
-            vfuncs[vfunc] = funcs[func]
+            vfuncs[vfunc] = func_item
             vfuncs[vfunc]['design'] = vdesign
         else:
-            vfuncs[vfunc]['pct'] += funcs[func]['pct']
-            vfuncs[vfunc]['calls'] += funcs[func]['calls']
-            vfuncs[vfunc]['sec'] += funcs[func]['sec']
+            vfuncs[vfunc]['pct'] += func_item['pct']
+            vfuncs[vfunc]['calls'] += func_item['calls']
+            vfuncs[vfunc]['sec'] += func_item['sec']
 
     for ftype in ['type', 'design', 'module']:
         missing = 100
@@ -136,9 +135,9 @@ def profcfunc(filename):
         print()
 
     design_width = 1
-    for func in vfuncs:
-        if design_width < len(vfuncs[func]['design']):
-            design_width = len(vfuncs[func]['design'])
+    for func, func_item in vfuncs.items():
+        if design_width < len(func_item['design']):
+            design_width = len(func_item['design'])
 
     print("Verilog code profile:")
     print("   These are split into three categories:")
diff --git a/docs/bin/vl_sphinx_extract b/docs/bin/vl_sphinx_extract
index 97d5b1ec5..c829482bf 100755
--- a/docs/bin/vl_sphinx_extract
+++ b/docs/bin/vl_sphinx_extract
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0112,C0114,C0115,C0116,C0301,R0201,R0903
+# pylint: disable=C0112,C0114,C0115,C0116,C0209,C0301,R0201,R0903
 # -*- Python -*- See copyright, etc below
 ######################################################################
 
@@ -14,7 +14,7 @@ class VlSphinxExtract:
     SkipBasenames = {}
 
     def process(self, filename):
-        with open(filename) as fhr:
+        with open(filename, "r", encoding="utf8") as fhr:
             fhw = None
             for line in fhr:
                 # =for VL_SPHINX_EXTRACT "file_to_write_to"
@@ -22,7 +22,7 @@ class VlSphinxExtract:
                 if match:
                     outname = match.group(1)
                     print("Writing %s" % outname)
-                    fhw = open(outname, "w")
+                    fhw = open(outname, "w", encoding="utf8")  # pylint: disable=consider-using-with
                     fhw.write(
                         ".. comment: generated by vl_sphinx_extract from " +
                         filename + "\n")
diff --git a/docs/bin/vl_sphinx_fix b/docs/bin/vl_sphinx_fix
index 3c18cb1c7..cc03c3b83 100755
--- a/docs/bin/vl_sphinx_fix
+++ b/docs/bin/vl_sphinx_fix
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0112,C0114,C0115,C0116,C0301,R0903
+# pylint: disable=C0112,C0114,C0115,C0116,C0209,C0301,R0903
 # -*- Python -*- See copyright, etc below
 ######################################################################
 
@@ -27,7 +27,7 @@ class VlSphinxFix:
 
     def _edit(self, filename):
         is_html = re.search(r'\.(html)$', filename)
-        with open(filename) as fhr:
+        with open(filename, "r", encoding="utf8") as fhr:
             origfile = fhr.read()
             wholefile = origfile
             # Option doesn't like spaces, so we use
@@ -43,7 +43,7 @@ class VlSphinxFix:
                 if self.debug:
                     print("Edit %s" % filename)
                 tempname = filename + ".tmp"
-                with open(tempname, "w") as fhw:
+                with open(tempname, "w", encoding="utf8") as fhw:
                     fhw.write(wholefile)
                 os.rename(tempname, filename)
 
diff --git a/docs/guide/conf.py b/docs/guide/conf.py
index fb9c66d1a..a10484a35 100644
--- a/docs/guide/conf.py
+++ b/docs/guide/conf.py
@@ -21,7 +21,7 @@ import sphinx_rtd_theme  # pylint: disable=wrong-import-position,
 
 def get_vlt_version():
     filename = "../../Makefile"
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         for line in fh:
             match = re.search(r"PACKAGE_VERSION_NUMBER *= *([a-z0-9.]+)", line)
             if match:
diff --git a/examples/xml_py/vl_file_copy b/examples/xml_py/vl_file_copy
index 1ff96328e..b221eba6a 100755
--- a/examples/xml_py/vl_file_copy
+++ b/examples/xml_py/vl_file_copy
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 # -*- Python -*- See copyright, etc below
-# pylint: disable=C0114,C0115,R0903
+# pylint: disable=C0114,C0115,C0209,R0903
 ######################################################################
 
 import argparse
@@ -20,24 +20,22 @@ class VlFileCopy:
     def __init__(
             self,
             verilator_args,  # presently all verilator options are passed-thru
-            # ideally this script would check against options mentioned in help
-        debug=0,
+            debug=0,
             output_dir='copied'):  # directory name we output file uses
 
         self.debug = debug
 
-        xml_temp = tempfile.NamedTemporaryFile()
-
-        vargs = [
-            '--xml-output',
-            xml_temp.name,
-            '--bbox-sys',  # Parse some stuff can't translate
-            '--bbox-unsup',
-            '--prefix vlxml'
-        ]  # So we know name of .xml output
-        vargs += verilator_args
-        self.run_verilator(vargs)
-        self.tree = ET.parse(xml_temp.name)
+        with tempfile.NamedTemporaryFile() as xml_temp:
+            vargs = [
+                '--xml-output',
+                xml_temp.name,
+                '--bbox-sys',  # Parse some stuff can't translate
+                '--bbox-unsup',
+                '--prefix vlxml'
+            ]  # So we know name of .xml output
+            vargs += verilator_args
+            self.run_verilator(vargs)
+            self.tree = ET.parse(xml_temp.name)
 
         os.makedirs(output_dir, 0o777, True)
 
diff --git a/examples/xml_py/vl_hier_graph b/examples/xml_py/vl_hier_graph
index 566250226..a2e82fabd 100755
--- a/examples/xml_py/vl_hier_graph
+++ b/examples/xml_py/vl_hier_graph
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 # -*- Python -*- See copyright, etc below
-# pylint: disable=C0103,C0114,C0115,C0115,C0116,R0914
+# pylint: disable=C0103,C0114,C0115,C0115,C0116,C0209,R0914
 ######################################################################
 
 import argparse
@@ -18,27 +18,25 @@ class VlHierGraph:
     def __init__(
             self,
             verilator_args,  # presently all verilator options are passed-thru
-            # ideally this script would check against options mentioned in help
-        debug=0,
+            debug=0,
             output_filename='graph.dot'):  # output filename
         self.debug = debug
         self.next_vertex_number = 0
         self.name_to_number = {}
 
-        xml_temp = tempfile.NamedTemporaryFile()
+        with tempfile.NamedTemporaryFile() as xml_temp:
+            vargs = [
+                '--xml-output',
+                xml_temp.name,
+                '--bbox-sys',  # Parse some stuff can't translate
+                '--bbox-unsup',
+                '--prefix vlxml'
+            ]  # So we know name of .xml output
+            vargs += verilator_args
+            self.run_verilator(vargs)
+            self.tree = ET.parse(xml_temp.name)
 
-        vargs = [
-            '--xml-output',
-            xml_temp.name,
-            '--bbox-sys',  # Parse some stuff can't translate
-            '--bbox-unsup',
-            '--prefix vlxml'
-        ]  # So we know name of .xml output
-        vargs += verilator_args
-        self.run_verilator(vargs)
-        self.tree = ET.parse(xml_temp.name)
-
-        with open(output_filename, "w") as fh:
+        with open(output_filename, "w", encoding="utf8") as fh:
             # For more serious purposes, use the python graphviz package instead
             fh.write("digraph {\n")
             fh.write("  dpi=300;\n")
diff --git a/nodist/code_coverage b/nodist/code_coverage
index 286397e91..5b6bcc53f 100755
--- a/nodist/code_coverage
+++ b/nodist/code_coverage
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0115,C0116,R0912,R0914,R0915,W0125,W0621,exec-used
+# pylint: disable=C0103,C0114,C0115,C0116,C0209,R0912,R0914,R0915,W0125,W0621,exec-used
 ######################################################################
 
 import argparse
@@ -26,7 +26,7 @@ if 'VERILATOR_ROOT' not in os.environ:
 def test():
     if not os.path.exists("nodist/code_coverage.dat"):
         sys.exit("%Error: Run code_coverage from the top of the verilator kit")
-    exec(open("./nodist/code_coverage.dat").read())
+    exec(open("./nodist/code_coverage.dat", "r", encoding="utf8").read())  # pylint: disable=consider-using-with
 
     if Args.stage_enabled[0]:
         ci_fold_start("distclean")
@@ -78,10 +78,11 @@ def test():
         os.makedirs(cc_dir, exist_ok=True)
         os.makedirs(cc_dir + "/info", exist_ok=True)
 
-        sp = subprocess.Popen("find . -print | grep .gcda",
+        with subprocess.Popen("find . -print | grep .gcda",
                               shell=True,
-                              stdout=subprocess.PIPE)
-        datout = sp.stdout.read()
+                              stdout=subprocess.PIPE) as sp:
+            datout = sp.stdout.read()
+
         dats = {}
         for dat in datout.splitlines():
             dat = dat.decode('utf-8')
@@ -97,10 +98,11 @@ def test():
                     del dats[dat]
                     break
 
-        sp = subprocess.Popen("find . -print | grep .gcno",
+        with subprocess.Popen("find . -print | grep .gcno",
                               shell=True,
-                              stdout=subprocess.PIPE)
-        datout = sp.stdout.read()
+                              stdout=subprocess.PIPE) as sp:
+            datout = sp.stdout.read()
+
         gcnos = {}
         for gcno in datout.splitlines():
             gcno = gcno.decode('utf-8')
@@ -204,8 +206,8 @@ def clone_sources(cc_dir):
             outfile = cc_dir + "/" + infile
             outpath = re.sub(r'/[^/]*$', '', outfile, count=1)
             os.makedirs(outpath, exist_ok=True)
-            with open(infile) as fh:
-                with open(outfile, "w") as ofh:
+            with open(infile, "r", encoding="utf8") as fh:
+                with open(outfile, "w", encoding="utf8") as ofh:
                     lineno = 0
                     for line in fh:
                         lineno += 1
@@ -249,7 +251,7 @@ def clone_sources(cc_dir):
 
 def cleanup_abs_paths_info(cc_dir, infile, outfile):
     lines = []
-    with open(infile) as fh:
+    with open(infile, "r", encoding="utf8") as fh:
         for line in fh:
             if re.search(r'^SF:', line):
                 line = re.sub(os.environ['VERILATOR_ROOT'] + '/',
@@ -261,7 +263,7 @@ def cleanup_abs_paths_info(cc_dir, infile, outfile):
                 # print("Remaining SF: "+line)
             lines.append(line)
 
-    with open(outfile, "w") as ofh:
+    with open(outfile, "w", encoding="utf8") as ofh:
         for line in lines:
             ofh.write(line)
 
@@ -270,14 +272,14 @@ def cleanup_abs_paths_json(cc_dir, infile, outfile):
     # Handcrafted cleanup, alternative would be to deserialize/serialize JSON,
     # but this is much faster
     lines = []
-    with open(infile) as fh:
+    with open(infile, "r", encoding="utf8") as fh:
         for line in fh:
             line = re.sub('"' + os.environ['VERILATOR_ROOT'] + '/', '"', line)
             line = re.sub('"' + cc_dir + '/', '"', line)
             line = re.sub(r'obj_dbg/verilog.y$', 'verilog.y', line)
             lines.append(line)
 
-    with open(outfile, "w") as ofh:
+    with open(outfile, "w", encoding="utf8") as ofh:
         for line in lines:
             ofh.write(line)
 
diff --git a/nodist/dot_importer b/nodist/dot_importer
index 29fe37fc2..cedf26696 100755
--- a/nodist/dot_importer
+++ b/nodist/dot_importer
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0115,C0116,C0301
+# pylint: disable=C0103,C0114,C0115,C0116,C0209,C0301
 ######################################################################
 
 import argparse
@@ -15,7 +15,7 @@ Edges = []
 
 
 def dotread(filename):
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         header = True
         vnum = 0
 
@@ -61,7 +61,7 @@ def dotread(filename):
 
 
 def cwrite(filename):
-    with open(filename, "w") as fh:
+    with open(filename, "w", encoding="utf8") as fh:
         fh.write("void V3GraphTestImport::dotImport() {\n")
         fh.write("    auto* gp = &m_graph;\n")
         for ver in sorted(Vertexes, key=lambda ver: ver['num']):
diff --git a/nodist/fuzzer/generate_dictionary b/nodist/fuzzer/generate_dictionary
index 546e48fcb..c03c899ed 100755
--- a/nodist/fuzzer/generate_dictionary
+++ b/nodist/fuzzer/generate_dictionary
@@ -45,8 +45,8 @@ def print_lines(a):
 
 def write_file(filename, contents):
     # str->str->void
-    f = open(filename, 'w')
-    f.write(contents)
+    with open(filename, "w", encoding="utf8") as fh:
+        fh.write(contents)
 
 
 def parse_line(s):
diff --git a/nodist/install_test b/nodist/install_test
index 7dcc2853a..0b1c66052 100755
--- a/nodist/install_test
+++ b/nodist/install_test
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0115,C0116,R0801,R0915
+# pylint: disable=C0103,C0114,C0115,C0116,C0209,R0801,R0915
 ######################################################################
 
 import argparse
diff --git a/src/astgen b/src/astgen
index f79ddc6ab..fe85a30cc 100755
--- a/src/astgen
+++ b/src/astgen
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0115,C0116,C0123,C0301,R0902,R0913,R0914,R0912,R0915,W0621
+# pylint: disable=C0103,C0114,C0115,C0116,C0123,C0209,C0301,C0302,R0902,R0913,R0914,R0912,R0915,W0621
 ######################################################################
 
 import argparse
@@ -80,7 +80,7 @@ class Node:
         # Sort sub-classes and convert to tuple, which marks completion
         self._subClasses = tuple(
             sorted(self._subClasses,
-                   key=lambda _: (bool(_._subClasses), _.name)))
+                   key=lambda _: (bool(_._subClasses), _.name)))  # pylint: disable=protected-access
 
         self._ordIdx = ordIdx
         ordIdx = ordIdx + 1
@@ -220,7 +220,7 @@ class Cpt:
         didln = False
 
         # Read the file and parse into list of functions that generate output
-        with open(self.in_filename) as fhi:
+        with open(self.in_filename, "r", encoding="utf8") as fhi:
             for line in fhi:
                 ln += 1
                 if not didln:
@@ -570,7 +570,7 @@ def read_types(filename, Nodes, prefix):
                     p=prefix, n=node.name))
         hasAstgenMembers = False
 
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         for (lineno, line) in enumerate(fh, start=1):
             line = line.strip()
             if not line:
@@ -715,7 +715,7 @@ def check_types(sortedTypes, prefix, abstractPrefix):
 
 
 def read_stages(filename):
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         n = 100
         for line in fh:
             line = re.sub(r'//.*$', '', line)
@@ -731,7 +731,7 @@ def read_stages(filename):
 
 def read_refs(filename):
     basename = re.sub(r'.*/', '', filename)
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         for line in fh:
             line = re.sub(r'//.*$', '', line)
             for match in re.finditer(r'\bnew\s*(Ast[A-Za-z0-9_]+)', line):
@@ -753,7 +753,7 @@ def read_refs(filename):
 
 
 def open_file(filename):
-    fh = open(filename, "w")
+    fh = open(filename, "w", encoding="utf8")  # pylint: disable=consider-using-with
     if re.search(r'\.txt$', filename):
         fh.write("// Generated by astgen\n")
     else:
diff --git a/src/bisonpre b/src/bisonpre
index 48f1761ff..664684c06 100755
--- a/src/bisonpre
+++ b/src/bisonpre
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0115,C0116,R0912,R0914,R0915,R1702,W0125
+# pylint: disable=C0103,C0114,C0115,C0116,C0209,R0912,R0914,R0915,R1702,W0125
 ######################################################################
 
 import argparse
@@ -17,7 +17,7 @@ def process():
 
     bison_version_check()
     supports_report = Bison_Version >= 2.3
-    supports_counter_examples = Bison_Version >= 3.8
+    # supports_counter_examples = Bison_Version >= 3.8
 
     clean_input(Args.input, tmp_prefix() + ".y")
 
@@ -88,10 +88,10 @@ def unlink_outputs():
 
 
 def bison_version_check():
-    sp = subprocess.Popen(Args.yacc + " --version",
+    with subprocess.Popen(Args.yacc + " --version",
                           shell=True,
-                          stdout=subprocess.PIPE)
-    out = str(sp.stdout.read())
+                          stdout=subprocess.PIPE) as sp:
+        out = str(sp.stdout.read())
     match = re.search(r'([0-9]+\.[0-9]+)', out)
     if match:
         v = float(match.group(1))
@@ -405,7 +405,7 @@ def clean_input(filename, outname):
             else:
                 lines.append(line)
 
-    with open(outname, "w") as fh:
+    with open(outname, "w", encoding="utf8") as fh:
         for line in lines:
             fh.write(line)
 
diff --git a/src/cppcheck_filtered b/src/cppcheck_filtered
index ce991abe3..78156e1e9 100755
--- a/src/cppcheck_filtered
+++ b/src/cppcheck_filtered
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0115,C0116,R0911,R0912,R0915,W0621
+# pylint: disable=C0103,C0114,C0115,C0116,C0209,R0911,R0912,R0915,W0621
 ######################################################################
 
 import argparse
@@ -155,11 +155,11 @@ def _suppress(filename, linenum, eid):
               file=sys.stderr)
         return False
 
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         lineno = 0
         for line in fh:
             lineno += 1
-            if ((lineno + 1) == linenum):
+            if (lineno + 1) == linenum:
                 match = re.search(
                     r'(cppcheck|cppcheck-has-bug|cppverilator)-suppress((\s+\S+)+)',
                     line)
diff --git a/src/vlcovgen b/src/vlcovgen
index 1c749e98c..e440dca43 100755
--- a/src/vlcovgen
+++ b/src/vlcovgen
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# pylint: disable=C0103,C0114,C0116,eval-used
+# pylint: disable=C0103,C0114,C0116,C0209,eval-used
 ######################################################################
 
 import argparse
@@ -13,7 +13,7 @@ Items = []
 
 
 def read_keys(filename):
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         for line in fh:
             line = re.sub(r'\/\/.*$', '', line)
             if re.match(r'^\s*$', line):
@@ -45,7 +45,7 @@ def write_keys(filename):
     orig = []
     out = []
 
-    with open(filename) as fh:
+    with open(filename, "r", encoding="utf8") as fh:
         deleting = False
         for line in fh:
             orig.append(line)
@@ -70,7 +70,7 @@ def write_keys(filename):
 
     ok = "".join(out) == "".join(orig)
     if not ok:
-        with open(filename, "w") as fhw:
+        with open(filename, "w", encoding="utf8") as fhw:
             fhw.write("".join(out))
 
 
diff --git a/test_regress/t/t_pipe_filter.pf b/test_regress/t/t_pipe_filter.pf
index 22af10c97..fe52740c7 100755
--- a/test_regress/t/t_pipe_filter.pf
+++ b/test_regress/t/t_pipe_filter.pf
@@ -27,7 +27,7 @@ for cmd in sys.stdin:
 
         wholefile = ""
         # It's faster to slurp the whole file then scan (if needed)
-        with open(filename) as fh:
+        with open(filename, "r", encoding="utf8") as fh:
             wholefile = fh.read()
 
         if 'example_lint' in wholefile:  # else short circuit