diff --git a/src/Generating/IntGen.h b/src/Generating/IntGen.h
index 94a17abd9..d7ed9275a 100644
--- a/src/Generating/IntGen.h
+++ b/src/Generating/IntGen.h
@@ -53,6 +53,10 @@ template <int SizeX, int SizeZ = SizeX>
 class cIntGen
 {
 public:
+	/** Force a virtual destructor in all descendants.
+	Descendants contain virtual functions and are referred to via pointer-to-base, so they need a virtual destructor. */
+	virtual ~cIntGen() {}
+
 	/** Holds the array of values generated by this class (descendant). */
 	typedef int Values[SizeX * SizeZ];