diff --git a/crypto/getcertheader.py b/crypto/getcertheader.py
index f0820c20..b323cd10 100755
--- a/crypto/getcertheader.py
+++ b/crypto/getcertheader.py
@@ -26,7 +26,7 @@ def to_c_uint32(x):
   nums = []
   for i in range(0x20):
     nums.append(x%(2**32))
-    x /= (2**32)
+    x //= (2**32)
   return "{"+'U,'.join(map(str, nums))+"U}"
 
 for fn in sys.argv[1:]:
diff --git a/python/__init__.py b/python/__init__.py
index 3f47ff8d..757d5409 100644
--- a/python/__init__.py
+++ b/python/__init__.py
@@ -232,7 +232,7 @@ class Panda(object):
   def flash_static(handle, code):
     # confirm flasher is present
     fr = handle.controlRead(Panda.REQUEST_IN, 0xb0, 0, 0, 0xc)
-    assert fr[4:8] == "\xde\xad\xd0\x0d"
+    assert fr[4:8] == b"\xde\xad\xd0\x0d"
 
     # unlock flash
     print("flash: unlocking")
@@ -274,7 +274,7 @@ class Panda(object):
       fn = os.path.join(BASEDIR, "board", fn)
 
     if code is None:
-      with open(fn) as f:
+      with open(fn, "rb") as f:
         code = f.read()
 
     # get version
@@ -364,7 +364,7 @@ class Panda(object):
       pass
 
   def get_version(self):
-    return self._handle.controlRead(Panda.REQUEST_IN, 0xd6, 0, 0, 0x40)
+    return bytes(self._handle.controlRead(Panda.REQUEST_IN, 0xd6, 0, 0, 0x40)).decode('utf8')
 
   def get_type(self):
     return self._handle.controlRead(Panda.REQUEST_IN, 0xc1, 0, 0, 0x40)