diff --git a/rehlds/engine/r_studio.cpp b/rehlds/engine/r_studio.cpp
index a6e625b..5ac33f2 100644
--- a/rehlds/engine/r_studio.cpp
+++ b/rehlds/engine/r_studio.cpp
@@ -59,6 +59,7 @@ r_studiocache_t rgStudioCache[STUDIO_CACHE_SIZE];
 int nCurrentHull;
 int nCurrentPlane;
 int r_cachecurrent;
+int g_studio_numhulls;
 
 int studio_hull_hitgroup[STUDIO_NUM_HULLS];
 hull_t studio_hull[STUDIO_NUM_HULLS];
@@ -704,6 +705,8 @@ hull_t *R_StudioHull(model_t *pModel, float frame, int sequence, const vec_t *an
 	}
 
 	*pNumHulls = (bSkipShield == 1) ? pstudiohdr->numhitboxes - 1 : pstudiohdr->numhitboxes;
+	g_studio_numhulls = *pNumHulls;
+
 	if (r_cachestudio.value != 0)
 	{
 #ifdef SWDS
diff --git a/rehlds/engine/studio_rehlds.h b/rehlds/engine/studio_rehlds.h
index a52ee38..631fb7f 100644
--- a/rehlds/engine/studio_rehlds.h
+++ b/rehlds/engine/studio_rehlds.h
@@ -105,3 +105,6 @@ void R_StudioAccumulateBoneVerts(vec_t *mins, vec_t *maxs, int *vertcount, vec_t
 int R_StudioComputeBounds(unsigned char *pBuffer, float *mins, float *maxs);
 int R_GetStudioBounds(const char *filename, float *mins, float *maxs);
 void R_ResetSvBlending(void);
+
+
+extern int g_studio_numhulls;
diff --git a/rehlds/public/rehlds/rehlds_api.h b/rehlds/public/rehlds/rehlds_api.h
index 3bb74c7..0cabb1a 100644
--- a/rehlds/public/rehlds/rehlds_api.h
+++ b/rehlds/public/rehlds/rehlds_api.h
@@ -199,7 +199,7 @@ struct RehldsFuncs_t {
 	void(*MSG_WriteBitVec3Coord)(const float *fa);
 	void(*MSG_EndBitWriting)(sizebuf_t *buf);
 	void*(*SZ_GetSpace)(sizebuf_t *buf, int length);
-	bool(*GetHitboxCorners)(int hitboxId, float* /* [8*3] */ corners);
+	bool(*GetHitboxCorners)(int hitboxId, float* /* [8*3] */ corners, int* pGroupId);
 };
 
 class IRehldsApi {
diff --git a/rehlds/rehlds/rehlds_api_impl.cpp b/rehlds/rehlds/rehlds_api_impl.cpp
index 7c6da87..7240a2f 100644
--- a/rehlds/rehlds/rehlds_api_impl.cpp
+++ b/rehlds/rehlds/rehlds_api_impl.cpp
@@ -65,7 +65,11 @@ DLL_FUNCTIONS* EXT_FUNC GetEntityInterface_api() {
 	return &gEntityInterface;
 }
 
-bool EXT_FUNC GetHitboxCorners(int hitboxId, float* /* [8*3] */ corners) {
+bool EXT_FUNC GetHitboxCorners(int hitboxId, float* /* [8*3] */ corners, int* pGroupId) {
+	if (hitboxId < 0 || hitboxId >= g_studio_numhulls) {
+		return false;
+	}
+
 	mplane_t* right = &studio_planes[hitboxId * 6 + 0 * 2 + 0];
 	mplane_t* left = &studio_planes[hitboxId * 6 + 0 * 2 + 1];
 	mplane_t* rear = &studio_planes[hitboxId * 6 + 1 * 2 + 0];
@@ -108,6 +112,10 @@ bool EXT_FUNC GetHitboxCorners(int hitboxId, float* /* [8*3] */ corners) {
 		return false;
 	corners[7 * 3 + 0] = p[0]; corners[7 * 3 + 1] = p[1]; corners[7 * 3 + 2] = p[2];
 
+	if (pGroupId) {
+		*pGroupId = studio_hull_hitgroup[hitboxId];
+	}
+
 	return true;
 }
 
diff --git a/rehlds/rehlds/rehlds_api_impl.h b/rehlds/rehlds/rehlds_api_impl.h
index 5362878..ef22f06 100644
--- a/rehlds/rehlds/rehlds_api_impl.h
+++ b/rehlds/rehlds/rehlds_api_impl.h
@@ -31,7 +31,7 @@
 #include "rehlds_api.h"
 #include "rehlds_interfaces_impl.h"
 
-extern bool GetHitboxCorners(int hitboxId, float* /* [8*3] */ corners);
+extern bool GetHitboxCorners(int hitboxId, float* /* [8*3] */ corners, int* pGroupId);
 
 //Steam_NotifyClientConnect
 typedef IHookChainImpl<qboolean, IGameClient*, const void*, unsigned int> CRehldsHook_Steam_NotifyClientConnect;