diff --git a/tools/finish.nim b/tools/finish.nim
index afb3d9fc10..fffc7bf477 100644
--- a/tools/finish.nim
+++ b/tools/finish.nim
@@ -156,6 +156,7 @@ proc main() =
         if incompat.len > 0:
           echo "The following *incompatible* MingW installations exist"
           for x in incompat: echo x
+          echo "*incompatible* means Nim and GCC disagree on the size of a pointer."
         echo "No compatible MingW candidates found " &
              "in the standard locations [Error]"
       else: