diff --git a/README.markdown b/README.markdown
index d0734d7..774a927 100644
--- a/README.markdown
+++ b/README.markdown
@@ -97,9 +97,10 @@ For more information: http://github.com/robertkrimen/otto/tree/master/underscore
 
 Go translates JavaScript-style regular expressions into something that is regexp package compatible.
 
-Unfortunately, JavaScript has positive and negative lookahead, which is not supported by Go's re2-like engine: https://code.google.com/p/re2/wiki/Syntax
+Unfortunately, JavaScript has positive lookahead, negative lookahead, and backreferencing,
+all of which are not supported by Go's re2-like engine: https://code.google.com/p/re2/wiki/Syntax
 
-A brief discussion of this limitation: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#!topic/golang-nuts/7qgSDWPIh_E
+A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#!topic/golang-nuts/7qgSDWPIh_E
 
 ### UTF-8 UTF-16
 
diff --git a/otto.go b/otto.go
index 32a4bb2..b9f79a6 100644
--- a/otto.go
+++ b/otto.go
@@ -94,9 +94,10 @@ Regular Expression Syntax
 
 Go translates JavaScript-style regular expressions into something that is regexp package compatible.
 
-Unfortunately, JavaScript has positive and negative lookahead, which is not supported by Go's re2-like engine: https://code.google.com/p/re2/wiki/Syntax
+Unfortunately, JavaScript has positive lookahead, negative lookahead, and backreferencing,
+all of which are not supported by Go's re2-like engine: https://code.google.com/p/re2/wiki/Syntax
 
-A brief discussion of this limitation: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#!topic/golang-nuts/7qgSDWPIh_E
+A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#!topic/golang-nuts/7qgSDWPIh_E
 
 UTF-8 UTF-16
 
diff --git a/parser_test.go b/parser_test.go
index fe39acd..b5ef0dd 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -1413,6 +1413,8 @@ Label '_' has already been declared
 	Unexpected token ILLEGAL
 	0:0:0
 	`)
+
+	test("/\\1/.source", "---\nInvalid regular expression: invalid escape sequence: `\\1`\n-:-:-")
 }
 
 func TestParseComment(t *testing.T) {