diff --git a/src/devices/cpu/m6502/m6502make.py b/src/devices/cpu/m6502/m6502make.py
index 8bcd85f8..557b1759 100755
--- a/src/devices/cpu/m6502/m6502make.py
+++ b/src/devices/cpu/m6502/m6502make.py
@@ -18,7 +18,7 @@ def load_opcodes(fname):
     opcodes = []
     logging.info("load_opcodes: %s", fname)
     try:
-        f = open(fname, "rU")
+        f = open(fname, "r")
     except Exception:
         err = sys.exc_info()[1]
         logging.error("cannot read opcodes file %s [%s]", fname, err)
@@ -41,7 +41,7 @@ def load_disp(fname):
     logging.info("load_disp: %s", fname)
     states = []
     try:
-        f = open(fname, "rU")
+        f = open(fname, "r")
     except Exception:
         err = sys.exc_info()[1]
         logging.error("cannot read display file %s [%s]", fname, err)
diff --git a/src/devices/cpu/m6809/m6809make.py b/src/devices/cpu/m6809/m6809make.py
index 8838b960..e1ea25db 100644
--- a/src/devices/cpu/m6809/m6809make.py
+++ b/src/devices/cpu/m6809/m6809make.py
@@ -16,7 +16,7 @@ def load_file(fname, lines):
 	if path != "":
 		path += '/'
 	try:
-		f = open(fname, "rU")
+		f = open(fname, "r")
 	except Exception:
 		err = sys.exc_info()[1]
 		sys.stderr.write("Cannot read opcodes file %s [%s]\n" % (fname, err))
diff --git a/src/devices/cpu/mcs96/mcs96make.py b/src/devices/cpu/mcs96/mcs96make.py
index b4844942..207208d2 100644
--- a/src/devices/cpu/mcs96/mcs96make.py
+++ b/src/devices/cpu/mcs96/mcs96make.py
@@ -73,7 +73,7 @@ class OpcodeList:
         self.ea = {}
         self.macros = {}
         try:
-            f = open(fname, "rU")
+            f = open(fname, "r")
         except Exception:
             err = sys.exc_info()[1]
             sys.stderr.write("Cannot read opcodes file %s [%s]\n" % (fname, err))
diff --git a/src/devices/cpu/tms57002/tmsmake.py b/src/devices/cpu/tms57002/tmsmake.py
index e2e12b5a..942ec095 100755
--- a/src/devices/cpu/tms57002/tmsmake.py
+++ b/src/devices/cpu/tms57002/tmsmake.py
@@ -323,7 +323,7 @@ class Instruction:
 def LoadLst(filename):
     instructions = []
     ins = None
-    for n, line in enumerate(open(filename, "rU")):
+    for n, line in enumerate(open(filename, "r")):
         line = line.rstrip()
         if not line and ins:
             # new lines separate intructions