diff --git a/go/ql/src/Security/CWE-020/IncompleteHostnameRegexp.qhelp b/go/ql/src/Security/CWE-020/IncompleteHostnameRegexp.qhelp
index cf4655dbae5..21368fca81b 100644
--- a/go/ql/src/Security/CWE-020/IncompleteHostnameRegexp.qhelp
+++ b/go/ql/src/Security/CWE-020/IncompleteHostnameRegexp.qhelp
@@ -41,6 +41,10 @@ domain such as wwwXexample.com.
Address this vulnerability by escaping . appropriately:
+
+You may also want to consider using raw string literals to avoid having to escape backslashes:
+
+
diff --git a/go/ql/src/Security/CWE-020/IncompleteHostnameRegexpGood2.go b/go/ql/src/Security/CWE-020/IncompleteHostnameRegexpGood2.go
new file mode 100644
index 00000000000..7c5df3f6742
--- /dev/null
+++ b/go/ql/src/Security/CWE-020/IncompleteHostnameRegexpGood2.go
@@ -0,0 +1,16 @@
+package main
+
+import (
+ "errors"
+ "net/http"
+ "regexp"
+)
+
+func checkRedirectGood(req *http.Request, via []*http.Request) error {
+ // GOOD: the host of `req.URL` must be `example.com`, `www.example.com` or `beta.example.com`
+ re := `^((www|beta)\.)?example\.com/`
+ if matched, _ := regexp.MatchString(re, req.URL.Host); matched {
+ return nil
+ }
+ return errors.New("Invalid redirect")
+}