diff --git a/include/tclap/CmdLineOutput.h b/include/tclap/CmdLineOutput.h
index c480666..71ee5a3 100644
--- a/include/tclap/CmdLineOutput.h
+++ b/include/tclap/CmdLineOutput.h
@@ -42,6 +42,12 @@ class CmdLineOutput
 {
 
 	public:
+
+		/**
+		 * Virtual destructor.
+		 */
+		virtual ~CmdLineOutput() {}
+
 		/**
 		 * Generates some sort of output for the USAGE. 
 		 * \param c - The CmdLine object the output is generated for. 
diff --git a/include/tclap/Visitor.h b/include/tclap/Visitor.h
index 746e2de..38ddcbd 100644
--- a/include/tclap/Visitor.h
+++ b/include/tclap/Visitor.h
@@ -37,6 +37,11 @@ class Visitor
 		 */
 		Visitor() { }
 
+		/**
+		 * Destructor. Does nothing.
+		 */
+		virtual ~Visitor() { }
+
 		/**
 		 * Does nothing. Should be overridden by child.
 		 */