diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 7271e3f32d82..ab041ae58b20 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -886,6 +886,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_tt *ttm)
 
 	if (gtt && gtt->userptr) {
 		kfree(ttm->sg);
+		ttm->sg = NULL;
 		ttm->page_flags &= ~TTM_PAGE_FLAG_SG;
 		return;
 	}