diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
index 9ad72f89ec..031b3a0084 100644
--- a/tools/dtoc/fdt.py
+++ b/tools/dtoc/fdt.py
@@ -469,7 +469,7 @@ class Fdt:
         if self._fname:
             self._fname = fdt_util.EnsureCompiled(self._fname)
 
-            with open(self._fname) as fd:
+            with open(self._fname, 'rb') as fd:
                 self._fdt_obj = libfdt.Fdt(fd.read())
 
     @staticmethod