diff --git a/src/swrenderer/scene/r_things.h b/src/swrenderer/scene/r_things.h
index 97ef51cbd..f0d9c098a 100644
--- a/src/swrenderer/scene/r_things.h
+++ b/src/swrenderer/scene/r_things.h
@@ -56,8 +56,6 @@ void R_DrawSprites ();
 void R_ClearSprites ();
 void R_DrawMasked ();
 
-void R_CheckOffscreenBuffer(int width, int height, bool spansonly);
-
 enum { DVF_OFFSCREEN = 1, DVF_SPANSONLY = 2, DVF_MIRRORED = 4 };
 
 void R_ClipVisSprite (vissprite_t *vis, int xl, int xh);
diff --git a/src/swrenderer/things/r_voxel.h b/src/swrenderer/things/r_voxel.h
index a3dc12e91..e3daa0d15 100644
--- a/src/swrenderer/things/r_voxel.h
+++ b/src/swrenderer/things/r_voxel.h
@@ -35,6 +35,7 @@ namespace swrenderer
 	kvxslab_t *R_GetSlabEnd(const FVoxelMipLevel &mip, int x, int y);
 	kvxslab_t *R_NextSlab(kvxslab_t *slab);
 
+	void R_CheckOffscreenBuffer(int width, int height, bool spansonly);
 	void R_DeinitRenderVoxel();
 
 	// [RH] A c-buffer. Used for keeping track of offscreen voxel spans.