diff --git a/src/dobjtype.cpp b/src/dobjtype.cpp
index 1d781c02c9..11fd04e82c 100644
--- a/src/dobjtype.cpp
+++ b/src/dobjtype.cpp
@@ -3374,27 +3374,6 @@ PClass *PClass::CreateDerivedClass(FName name, unsigned int size)
 	return type;
 }
 
-//==========================================================================
-//
-// PClass :: Extend
-//
-// Add <extension> bytes to the end of this class and possibly more to meet
-// alignment restrictions. Returns the start of the extended block.
-//
-//==========================================================================
-
-unsigned int PClass::Extend(unsigned int extension, unsigned int alignment)
-{
-	assert(this->bRuntimeClass);
-
-	unsigned int oldsize = Size;
-	unsigned int padto = (oldsize + alignment - 1) & ~(alignment - 1);
-	Size = padto + extension;
-	Defaults = (BYTE *)M_Realloc(Defaults, Size);
-	memset(Defaults + oldsize, 0, Size - oldsize);
-	return padto;
-}
-
 //==========================================================================
 //
 // PClass :: AddField
diff --git a/src/dobjtype.h b/src/dobjtype.h
index 5ad5757f3e..6798045663 100644
--- a/src/dobjtype.h
+++ b/src/dobjtype.h
@@ -725,8 +725,6 @@ public:
 	void InsertIntoHash();
 	DObject *CreateNew() const;
 	PClass *CreateDerivedClass(FName name, unsigned int size);
-	unsigned int Extend(unsigned int extension, unsigned int alignment);
-	unsigned int Extend(const PType *type) { return Extend(type->Size, type->Align); }
 	PField *AddField(FName name, PType *type, DWORD flags=0) override;
 	void InitializeActorInfo();
 	void BuildFlatPointers();