diff --git a/src/emu/cpu/m6502/m6502make.py b/src/emu/cpu/m6502/m6502make.py
index da29fc722a..3de641dd69 100755
--- a/src/emu/cpu/m6502/m6502make.py
+++ b/src/emu/cpu/m6502/m6502make.py
@@ -16,7 +16,7 @@ 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)
@@ -39,7 +39,7 @@ 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/emu/cpu/m6809/m6809make.py b/src/emu/cpu/m6809/m6809make.py
index c3d5b0f66e..79f6f90cdd 100644
--- a/src/emu/cpu/m6809/m6809make.py
+++ b/src/emu/cpu/m6809/m6809make.py
@@ -14,7 +14,7 @@ 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/emu/cpu/mcs96/mcs96make.py b/src/emu/cpu/mcs96/mcs96make.py
index ec5ec37a78..7ab806a653 100644
--- a/src/emu/cpu/mcs96/mcs96make.py
+++ b/src/emu/cpu/mcs96/mcs96make.py
@@ -71,7 +71,7 @@ def __init__(self, fname, is_196):
         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/emu/cpu/tms57002/tmsmake.py b/src/emu/cpu/tms57002/tmsmake.py
index 62092097d9..78f9fe43cd 100755
--- a/src/emu/cpu/tms57002/tmsmake.py
+++ b/src/emu/cpu/tms57002/tmsmake.py
@@ -326,7 +326,7 @@ def ins_cmp_dasm(a, b):
 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