diff --git a/source/blender/blenkernel/BKE_particle.h b/source/blender/blenkernel/BKE_particle.h
index 9f44d3c47cb..cf02efc34ac 100644
--- a/source/blender/blenkernel/BKE_particle.h
+++ b/source/blender/blenkernel/BKE_particle.h
@@ -55,6 +55,9 @@ struct IpoCurve;
 struct LinkNode;
 struct KDTree;
 struct RNG;
+struct SurfaceModifierData;
+struct BVHTreeRay;
+struct BVHTreeRayHit; 
 
 typedef struct ParticleEffectorCache {
 	struct ParticleEffectorCache *next, *prev;