diff --git a/Misc/gdbinit b/Misc/gdbinit
index bb10bdba799aa6..a21b28e176170a 100644
--- a/Misc/gdbinit
+++ b/Misc/gdbinit
@@ -149,7 +149,7 @@ define pystackv
 end
 
 # generally useful macro to print a Unicode string
-def pu
+define pu
   set $uni = $arg0
   set $i = 0
   while (*$uni && $i++<100)