diff --git a/source/blender/editors/sculpt_paint/sculpt.cc b/source/blender/editors/sculpt_paint/sculpt.cc
index 2d43d830ac3..70274eeefcb 100644
--- a/source/blender/editors/sculpt_paint/sculpt.cc
+++ b/source/blender/editors/sculpt_paint/sculpt.cc
@@ -946,6 +946,8 @@ bool vert_is_boundary(const Span<bool> /*hide_poly*/,
     case SUBDIV_CCG_ADJACENT_NONE:
       return false;
   }
+  BLI_assert_unreachable();
+  return false;
 }
 
 bool vert_is_boundary(BMVert *vert)