diff --git a/mode/perl.py b/mode/perl.py
index 5610a3d..b2a9c8d 100644
--- a/mode/perl.py
+++ b/mode/perl.py
@@ -85,9 +85,9 @@ class StrictStringGrammar(Grammar): rules = [
     PatternRule('data', r"[^\\']+"),
 ]
 class StringGrammar(Grammar):
-    rules = _make_string_rules('"') + [PatternRule('data', '[^\\"]+')]
+    rules = _make_string_rules('"') + [PatternRule('data', r'[^\\"]+')]
 class EvalGrammar(Grammar):
-    rules = _make_string_rules('`') + [PatternRule('data', '[^\\`]+')]
+    rules = _make_string_rules('`') + [PatternRule('data', r'[^\\`]+')]
 
 class TranslateGrammar1(Grammar):
     rules = [PatternRule('data', r"(?:\\.|[^\\/])")]