diff --git a/.gitignore b/.gitignore
index 6a2a1fa..269e2b3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,4 +7,5 @@ ldoc*
 telescope*
 hkl
 debug*
-profiler*
\ No newline at end of file
+profiler*
+.DS_Store
\ No newline at end of file
diff --git a/jumper/grid.lua b/jumper/grid.lua
index 02e5c3c..1a4fd25 100644
--- a/jumper/grid.lua
+++ b/jumper/grid.lua
@@ -333,7 +333,7 @@ if (...) then
 	-- myGrid:imap(nothing)
   function Grid:imap(f,...)
     for node in self:iter() do
-      node = f(node,...)
+      f(node,...)
     end
 		return self
   end
@@ -356,7 +356,7 @@ if (...) then
 	-- myGrid:imap(1,1,6,6,nothing)
   function Grid:imapRange(lx,ly,ex,ey,f,...)
     for node in self:iter(lx,ly,ex,ey) do
-      node = f(node,...)
+      f(node,...)
     end
 		return self
   end