diff --git a/src/namedef.h b/src/namedef.h
index d06ca9ccc..2f312d6a0 100644
--- a/src/namedef.h
+++ b/src/namedef.h
@@ -306,6 +306,7 @@ xx(CallACS)
 xx(Sqrt)
 xx(CheckClass)
 xx(IsPointerEqual)
+xx(CountInv)
 xx(Pick)
 xx(Mass)
 xx(VelX)
diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index ba5bc7f47..3f2300ece 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -217,6 +217,39 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, IsPointerEqual)
 	return 0;
 }
 
+//==========================================================================
+//
+// CountInv
+//
+// NON-ACTION function to return the inventory count of an item.
+//
+//==========================================================================
+
+DEFINE_ACTION_FUNCTION_PARAMS(AActor, CountInv)
+{
+	if (numret > 0)
+	{
+		assert(ret != NULL);
+		PARAM_PROLOGUE;
+		PARAM_OBJECT(self, AActor);
+		PARAM_CLASS(itemtype, AInventory);
+		PARAM_INT_OPT(pick_pointer)		{ pick_pointer = AAPTR_DEFAULT; }
+
+		self = COPY_AAPTR(self, pick_pointer);
+		if (self == NULL || itemtype == NULL)
+		{
+			ret->SetInt(false);
+		}
+		else
+		{
+			AInventory *item = self->FindInventory(itemtype);
+			ret->SetInt(item ? item->Amount : 0);
+			return 1;
+		}
+	}
+	return 0;
+}
+
 //==========================================================================
 //
 // A_RearrangePointers
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index 1f7efd895..0d0e98261 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -35,6 +35,7 @@ ACTOR Actor native //: Thinker
 	// Functions
 	native bool CheckClass(class<Actor> checkclass, int ptr_select = AAPTR_DEFAULT, bool match_superclass = false);
 	native bool IsPointerEqual(int ptr_select1, int ptr_select2);
+	native int	CountInv(class<Inventory> itemtype, int ptr_select = AAPTR_DEFAULT);
 
 	// Action functions