diff --git a/src/actor.h b/src/actor.h
index 9c4fd9ff7..13ddf91fa 100644
--- a/src/actor.h
+++ b/src/actor.h
@@ -30,9 +30,7 @@
 #include "dthinker.h"
 
 
-// States are tied to finite states are
-//	tied to animation frames.
-// Needs precompiled tables/data structures.
+// States are tied to finite states are tied to animation frames.
 #include "info.h"
 
 #include "doomdef.h"
@@ -40,6 +38,7 @@
 #include "r_data/renderstyle.h"
 #include "s_sound.h"
 #include "memarena.h"
+#include "g_level.h"
 
 struct subsector_t;
 //
@@ -715,7 +714,16 @@ public:
 
 	// What species am I?
 	virtual FName GetSpecies();
-	
+
+	fixed_t GetBobOffset(fixed_t ticfrac=0) const
+	{
+		 if (!(flags2 & MF2_FLOATBOB))
+		 {
+			 return 0;
+		 }
+		 return finesine[MulScale22(((FloatBobPhase + level.maptime) << FRACBITS) + ticfrac, FINEANGLES) & FINEMASK] * 8;
+	}
+
 	// Enter the crash state
 	void Crash();
 
diff --git a/src/r_things.cpp b/src/r_things.cpp
index 80d0a75bc..459ebdbce 100644
--- a/src/r_things.cpp
+++ b/src/r_things.cpp
@@ -512,13 +512,7 @@ void R_ProjectSprite (AActor *thing, int fakeside, F3DFloor *fakefloor, F3DFloor
 	// [RH] Interpolate the sprite's position to make it look smooth
 	fx = thing->PrevX + FixedMul (r_TicFrac, thing->x - thing->PrevX);
 	fy = thing->PrevY + FixedMul (r_TicFrac, thing->y - thing->PrevY);
-	fz = thing->PrevZ + FixedMul (r_TicFrac, thing->z - thing->PrevZ);
-
-	// [RH] Make floatbobbing a renderer-only effect.
-	if (thing->flags2 & MF2_FLOATBOB)
-	{
-		fz += finesine[MulScale22(((thing->FloatBobPhase + level.maptime) << FRACBITS) + r_TicFrac, FINEANGLES) & FINEMASK] * 8;
-	}
+	fz = thing->PrevZ + FixedMul (r_TicFrac, thing->z - thing->PrevZ) + thing->GetBobOffset(r_TicFrac);
 
 	// transform the origin point
 	tr_x = fx - viewx;