diff --git a/tools/check_encoding.py b/tools/check_encoding.py
index 1d24d4679..d964ebaab 100755
--- a/tools/check_encoding.py
+++ b/tools/check_encoding.py
@@ -15,11 +15,7 @@
         if suffix in SUFFICES:
             with open(os.path.join(root, file)) as f:
                 contents = f.read()
-            try:
-                contents.decode('ascii')
-            except UnicodeDecodeError:
+            if not contents.isascii():
                 for line in contents.split('\n'):
-                    try:
-                        line.decode('ascii')
-                    except UnicodeDecodeError:
+                    if not line.isascii():
                         raise Exception('Detected non-ascii characters in file {}, line: "{}"'.format(os.path.join(root, file), line))