diff --git a/src/parsing/syntax_definition.rs b/src/parsing/syntax_definition.rs
index d73c3e7c..d9498555 100644
--- a/src/parsing/syntax_definition.rs
+++ b/src/parsing/syntax_definition.rs
@@ -241,6 +241,9 @@ where
 
         last_was_escape = c == '\\' && !last_was_escape;
     }
+    if last_was_escape {
+        reg_str.push('\\');
+    }
     reg_str
 }