diff --git a/PIL/GimpPaletteFile.py b/PIL/GimpPaletteFile.py
index 4bf3ca36a..e4b4641e5 100644
--- a/PIL/GimpPaletteFile.py
+++ b/PIL/GimpPaletteFile.py
@@ -41,7 +41,7 @@ class GimpPaletteFile(object):
             if not s:
                 break
             # skip fields and comment lines
-            if re.match(b"\w+:|#", s):
+            if re.match(br"\w+:|#", s):
                 continue
             if len(s) > 100:
                 raise SyntaxError("bad palette file")
diff --git a/PIL/PngImagePlugin.py b/PIL/PngImagePlugin.py
index a5f4c3f42..4d6f9d7ff 100644
--- a/PIL/PngImagePlugin.py
+++ b/PIL/PngImagePlugin.py
@@ -48,7 +48,7 @@ i8 = _binary.i8
 i16 = _binary.i16be
 i32 = _binary.i32be
 
-is_cid = re.compile(b"\w\w\w\w").match
+is_cid = re.compile(br"\w\w\w\w").match
 
 
 _MAGIC = b"\211PNG\r\n\032\n"
diff --git a/PIL/XbmImagePlugin.py b/PIL/XbmImagePlugin.py
index bca882866..d0b0e47ab 100644
--- a/PIL/XbmImagePlugin.py
+++ b/PIL/XbmImagePlugin.py
@@ -26,7 +26,7 @@ __version__ = "0.6"
 
 # XBM header
 xbm_head = re.compile(
-    b"\s*#define[ \t]+.*_width[ \t]+(?P<width>[0-9]+)[\r\n]+"
+    br"\s*#define[ \t]+.*_width[ \t]+(?P<width>[0-9]+)[\r\n]+"
     b"#define[ \t]+.*_height[ \t]+(?P<height>[0-9]+)[\r\n]+"
     b"(?P<hotspot>"
     b"#define[ \t]+[^_]*_x_hot[ \t]+(?P<xhot>[0-9]+)[\r\n]+"