diff --git a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/Protobuf.xtext b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/Protobuf.xtext
index ad6e825..6c6c4d3 100644
--- a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/Protobuf.xtext
+++ b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/Protobuf.xtext
@@ -143,7 +143,8 @@
   SL_STRING (SL_STRING)*;
 
 terminal SL_STRING:
-  '"' ('\\' ('b' | 't' | 'n' | 'f' | 'r' | 'u' | '"' | "'" | '\\' | UNICODE_OCTAL) | !('\\' | '"'))* '"' (WS)*;
+  '"' ('\\' ('b' | 't' | 'n' | 'f' | 'r' | 'u' | '"' | "'" | '\\' | UNICODE_OCTAL) | !('\\' | '"'))* '"' (WS)* |
+  "'" ('\\' ('b' | 't' | 'n' | 'f' | 'r' | 'u' | '"' | "'" | '\\' | UNICODE_OCTAL) | !('\\' | "'"))* "'" (WS)*;
 
 terminal UNICODE_OCTAL:
   ('0'..'3')('0'..'7')('0'..'7');