diff --git a/src/dobjtype.cpp b/src/dobjtype.cpp
index 92e37333a2..45dc4ee48d 100644
--- a/src/dobjtype.cpp
+++ b/src/dobjtype.cpp
@@ -991,6 +991,27 @@ PStruct *NewStruct(FName name, DObject *outer)
 
 IMPLEMENT_CLASS(PPrototype)
 
+//==========================================================================
+//
+// PPrototype - Default Constructor
+//
+//==========================================================================
+
+PPrototype::PPrototype()
+{
+}
+
+//==========================================================================
+//
+// PPrototype - Parameterized Constructor
+//
+//==========================================================================
+
+PPrototype::PPrototype(const TArray<PType *> &rettypes, const TArray<PType *> &argtypes)
+: ArgumentTypes(argtypes), ReturnTypes(rettypes)
+{
+}
+
 //==========================================================================
 //
 // PPrototype :: IsMatch
@@ -1031,6 +1052,27 @@ size_t PPrototype::PropagateMark()
 		Super::PropagateMark();
 }
 
+//==========================================================================
+//
+// NewPrototype
+//
+// Returns a PPrototype for the given return and argument types, making sure
+// not to create duplicates.
+//
+//==========================================================================
+
+PPrototype *NewPrototype(const TArray<PType *> &rettypes, const TArray<PType *> &argtypes)
+{
+	size_t bucket;
+	PType *proto = TypeTable.FindType(RUNTIME_CLASS(PPrototype), (intptr_t)&argtypes, (intptr_t)&rettypes, &bucket);
+	if (proto == NULL)
+	{
+		proto = new PPrototype(rettypes, argtypes);
+		TypeTable.AddType(proto, RUNTIME_CLASS(PPrototype), (intptr_t)&argtypes, (intptr_t)&rettypes, bucket);
+	}
+	return static_cast<PPrototype *>(proto);
+}
+
 /* PFunction **************************************************************/
 
 IMPLEMENT_CLASS(PFunction)
diff --git a/src/dobjtype.h b/src/dobjtype.h
index e3fb2603a0..a927a32989 100644
--- a/src/dobjtype.h
+++ b/src/dobjtype.h
@@ -425,12 +425,16 @@ class PPrototype : public PCompoundType
 {
 	DECLARE_CLASS(PPrototype, PCompoundType);
 public:
+	PPrototype(const TArray<PType *> &rettypes, const TArray<PType *> &argtypes);
+
 	TArray<PType *> ArgumentTypes;
 	TArray<PType *> ReturnTypes;
 
 	size_t PropagateMark();
 	virtual bool IsMatch(intptr_t id1, intptr_t id2) const;
 	virtual void GetTypeIDs(intptr_t &id1, intptr_t &id2) const;
+protected:
+	PPrototype();
 };
 
 // TBD: Should we really support overloading?
@@ -589,6 +593,7 @@ PClassPointer *NewClassPointer(PClass *restrict);
 PClassWaitingForParent *NewUnknownClass(FName myname, FName parentname);
 PEnum *NewEnum(FName name, DObject *outer);
 PStruct *NewStruct(FName name, DObject *outer);
+PPrototype *NewPrototype(const TArray<PType *> &rettypes, const TArray<PType *> &argtypes);
 
 // Built-in types -----------------------------------------------------------