diff --git a/advtrains/api_doc.txt b/advtrains/api_doc.txt
index 9ea3cb6..e86f16b 100644
--- a/advtrains/api_doc.txt
+++ b/advtrains/api_doc.txt
@@ -99,8 +99,9 @@ advtrains.register_wagon(name, prototype, description, inventory_image)
 	^- optional: Execute custom code on every step
 	custom_on_activate = function(self, dtime_s) end
 	^- optional: Execute custom code on activate. Staticdata does not need to be saved and restored since all properties written in 'self' are preserved over unloads.
-	update_animation = function(self, velocity) end
-	^- optional: Function that is called whenever the train's velocity changes or every 2 seconds. Used to call 'self.object:update_animation()' if needed. 
+	custom_on_velocity_change = function(self, velocity, old_velocity) end
+	^- optional: Function that is called whenever the train's velocity changes or every 2 seconds. Used to call 'self.object:update_animation()' if needed.
+	^- for compatibility reasons the name 'update_animation' for this function is still supported. 
 
 }
 
@@ -164,4 +165,4 @@ minetest.register_node(nodename, {
 		on_train_leave=function(pos, train_id) end
 		^- called when a train leaves the rail
 	}
-})
\ No newline at end of file
+})
diff --git a/advtrains/wagons.lua b/advtrains/wagons.lua
index 3892813..4306b50 100644
--- a/advtrains/wagons.lua
+++ b/advtrains/wagons.lua
@@ -502,12 +502,16 @@ function wagon:on_step(dtime)
 			self.object:setyaw(yaw)
 			self.updatepct_timer=2
 			if self.update_animation then
-				self:update_animation(gp.velocity)
+				self:update_animation(gp.velocity, self.old_velocity)
+			end
+			if self.custom_on_velocity_change then
+				self:custom_on_velocity_change(gp.velocity, self.old_velocity)
 			end
 		end
 		
 		
 		self.old_velocity_vector=velocityvec
+		self.old_velocity = gp.velocity
 		self.old_acceleration_vector=accelerationvec
 		self.old_yaw=yaw
 		atprintbm("wagon step", t)
diff --git a/advtrains_train_steam/init.lua b/advtrains_train_steam/init.lua
index 315104a..37c63a0 100755
--- a/advtrains_train_steam/init.lua
+++ b/advtrains_train_steam/init.lua
@@ -37,7 +37,7 @@ advtrains.register_wagon("newlocomotive", {
 	visual_size = {x=1, y=1},
 	wagon_span=2.3,
 	collisionbox = {-1.0,-0.5,-1.0, 1.0,2.5,1.0},
-	update_animation=function(self, velocity)
+	custom_on_velocity_change=function(self, velocity)
 		if self.old_anim_velocity~=advtrains.abs_ceil(velocity) then
 			self.object:set_animation({x=1,y=80}, advtrains.abs_ceil(velocity)*15, 0, true)
 			self.old_anim_velocity=advtrains.abs_ceil(velocity)
@@ -105,7 +105,7 @@ advtrains.register_wagon("detailed_steam_engine", {
 	visual_size = {x=1, y=1},
 	wagon_span=2.05,
 	collisionbox = {-1.0,-0.5,-1.0, 1.0,2.5,1.0},
-	update_animation=function(self, velocity)
+	custom_on_velocity_change=function(self, velocity)
 		if self.old_anim_velocity~=advtrains.abs_ceil(velocity) then
 			self.object:set_animation({x=1,y=80}, advtrains.abs_ceil(velocity)*15, 0, true)
 			self.old_anim_velocity=advtrains.abs_ceil(velocity)