diff --git a/ref/gl/gl_cull.c b/ref/gl/gl_cull.c
index d432b073..b4fad790 100644
--- a/ref/gl/gl_cull.c
+++ b/ref/gl/gl_cull.c
@@ -40,23 +40,20 @@ qboolean R_CullBox( const vec3_t mins, const vec3_t maxs )
 R_CullModel
 =============
 */
-int R_CullModel( cl_entity_t *e, const vec3_t absmin, const vec3_t absmax )
+qboolean R_CullModel( cl_entity_t *e, const vec3_t absmin, const vec3_t absmax )
 {
 	if( e == tr.viewent )
 	{
 		if( ENGINE_GET_PARM( PARM_DEV_OVERVIEW ))
-			return 1;
+			return true;
 
 		if( RP_NORMALPASS() && !ENGINE_GET_PARM( PARM_THIRDPERSON ) && CL_IsViewEntityLocalPlayer())
-			return 0;
+			return false;
 
-		return 1;
+		return true;
 	}
 
-	if( R_CullBox( absmin, absmax ))
-		return 1;
-
-	return 0;
+	return R_CullBox( absmin, absmax );
 }
 
 /*
diff --git a/ref/gl/gl_local.h b/ref/gl/gl_local.h
index 37ed0781..f28ee51b 100644
--- a/ref/gl/gl_local.h
+++ b/ref/gl/gl_local.h
@@ -328,7 +328,7 @@ qboolean R_BeamCull( const vec3_t start, const vec3_t end, qboolean pvsOnly );
 //
 // gl_cull.c
 //
-int R_CullModel( cl_entity_t *e, const vec3_t absmin, const vec3_t absmax );
+qboolean R_CullModel( cl_entity_t *e, const vec3_t absmin, const vec3_t absmax );
 qboolean R_CullBox( const vec3_t mins, const vec3_t maxs );
 int R_CullSurface( msurface_t *surf, gl_frustum_t *frustum, uint clipflags );
 
diff --git a/ref/gl/gl_studio.c b/ref/gl/gl_studio.c
index d8298e40..ddae6c0d 100644
--- a/ref/gl/gl_studio.c
+++ b/ref/gl/gl_studio.c
@@ -219,7 +219,7 @@ static qboolean R_StudioComputeBBox( vec3_t bbox[8] )
 		return false;
 
 	// check if we have valid mins\maxs
-	if( !VectorCompare( vec3_origin, RI.currentmodel->mins ))
+	if( !VectorIsNull( RI.currentmodel->mins ) && !VectorIsNull( RI.currentmodel->maxs ))
 	{
 		// clipping bounding box
 		VectorCopy( RI.currentmodel->mins, mins );
diff --git a/ref/soft/r_studio.c b/ref/soft/r_studio.c
index 6437a0ac..acaf4940 100644
--- a/ref/soft/r_studio.c
+++ b/ref/soft/r_studio.c
@@ -211,7 +211,7 @@ static qboolean R_StudioComputeBBox( vec3_t bbox[8] )
 		return false;
 
 	// check if we have valid mins\maxs
-	if( !VectorCompare( vec3_origin, RI.currentmodel->mins ))
+	if( !VectorIsNull( RI.currentmodel->mins ) && !VectorIsNull( RI.currentmodel->maxs ))
 	{
 		// clipping bounding box
 		VectorCopy( RI.currentmodel->mins, mins );