diff --git a/src/CLI2.cpp b/src/CLI2.cpp
index cc8d884a8..1447c9e32 100644
--- a/src/CLI2.cpp
+++ b/src/CLI2.cpp
@@ -2029,20 +2029,6 @@ bool CLI2::isUUIDList (const std::string& raw) const
   return false;
 }
 
-////////////////////////////////////////////////////////////////////////////////
-// The non-g case is caught by ::isPattern, but not categorized, so it doesn't
-// matter.
-bool CLI2::isSubstitution (const std::string& raw) const
-{
-  if (raw.length () > 3             &&      // /x// = length 4
-      raw[0] == '/'                 &&
-      raw[raw.length () - 2] == '/' &&
-      raw[raw.length () - 1] == 'g')
-    return true;
-
-  return false;
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // Covers attribute and attribute modifiers.
 // <attr>.[~]<mod>[:=]...
diff --git a/src/CLI2.h b/src/CLI2.h
index 07c44e111..f22c81c86 100644
--- a/src/CLI2.h
+++ b/src/CLI2.h
@@ -130,7 +130,6 @@ private:
   void decomposeModSubstitutions ();
 
   bool isUUIDList       (const std::string&) const;
-  bool isSubstitution   (const std::string&) const;
   bool isAttribute      (const std::string&) const;
   bool isOperator       (const std::string&) const;
   bool isName           (const std::string&) const;