diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index 1e15a5c33..9a8e02468 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -250,6 +250,41 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, CountInv)
 	return 0;
 }
 
+//==========================================================================
+//
+// GetDistance
+//
+// NON-ACTION function to get the distance in double.
+//
+//==========================================================================
+DEFINE_ACTION_FUNCTION_PARAMS(AActor, GetDistance)
+{
+	if (numret > 0)
+	{
+		assert(ret != NULL);
+		PARAM_PROLOGUE;
+		PARAM_OBJECT(self, AActor);
+		PARAM_BOOL(checkz);
+		PARAM_INT_OPT(ptr) { ptr = AAPTR_TARGET; }
+
+		AActor *target = COPY_AAPTR(self, ptr);
+
+		if (!target || target == self)
+		{
+			ret->SetFloat(false);
+		}
+		else
+		{
+			fixedvec3 diff = self->Vec3To(target);
+			diff.z += (target->height - self->height) / 2;
+			const double lengthsquared = TVector3<double>(diff.x, diff.y, diff.z).LengthSquared();
+			ret->SetFloat(lengthsquared);
+		}
+		return 1;
+	}
+	return 0;
+}
+
 //==========================================================================
 //
 // A_RearrangePointers
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index 8e30693cf..48ee9f68f 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -41,6 +41,7 @@ ACTOR Actor native //: Thinker
 	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);
+	native float GetDistance(bool checkz, int ptr = AAPTR_DEFAULT);
 
 	// Action functions
 	// Meh, MBF redundant functions. Only for DeHackEd support.