diff --git a/pronsole.py b/pronsole.py
index 47a0e53..7e15d4f 100755
--- a/pronsole.py
+++ b/pronsole.py
@@ -182,6 +182,15 @@ class pronsole(cmd.Cmd):
             print "Empty macro - cancelled"
         del self.cur_macro,self.cur_macro_name,self.cur_macro_def
         
+    def start_macro(self,macro_name,prev_definition="",suppress_instructions=False):
+        if not self.processing_rc and not suppress_instructions:
+            print "Enter macro using indented lines, end with empty line"
+        self.cur_macro_name = macro_name
+        self.cur_macro_def = ""
+        self.cur_macro = "def macro(self,*arg):\n"
+        self.onecmd = self.hook_macro # override onecmd temporarily
+        self.prompt="..>"
+        
     def do_macro(self,args):
         if args.strip()=="":
             self.print_topics("User-defined macros",self.macros.keys(),15,80)
@@ -214,13 +223,10 @@ class pronsole(cmd.Cmd):
                 self.cur_macro = "def macro(self,*arg):\n  self.onecmd('"+macro_def+"'.format(*arg))\n"
             self.end_macro()
             return
-        if not self.processing_rc:
-            print "Enter macro using indented lines, end with empty line"
-        self.cur_macro_name = macro_name
-        self.cur_macro_def = ""
-        self.cur_macro = "def macro(self,*arg):\n"
-        self.onecmd = self.hook_macro # override onecmd temporarily
-        self.prompt="..>"
+        if self.macros.has_key(macro_name):
+            self.start_macro(macro_name,self.macros[macro_name])
+        else:
+            self.start_macro(macro_name)
     
     def help_macro(self):
         print "Define single-line macro: macro <name> <definition>"
diff --git a/pronterface.py b/pronterface.py
index 94f9b4f..cf287f0 100755
--- a/pronterface.py
+++ b/pronterface.py
@@ -178,6 +178,28 @@ class PronterWindow(wx.Frame,pronsole.pronsole):
         except:
             print "You must enter a temperature."
             
+    def start_macro(self,macro_name,old_macro_definition=""):
+        if not self.processing_rc:
+            def cb(definition):
+                if "\n" not in definition and len(definition.strip())>0:
+                    macro_def = definition.strip()
+                    self.cur_macro_def = macro_def
+                    self.cur_macro_name = macro_name
+                    if macro_def.startswith("!"):
+                        self.cur_macro = "def macro(self,*arg):\n  "+macro_def[1:]+"\n"
+                    else:
+                        self.cur_macro = "def macro(self,*arg):\n  self.onecmd('"+macro_def+"'.format(*arg))\n"
+                    self.end_macro()
+                    return
+                pronsole.pronsole.start_macro(self,macro_name,True)
+                for line in definition.split("\n"):
+                    if hasattr(self,"cur_macro_def"):
+                        self.hook_macro(line)
+                if hasattr(self,"cur_macro_def"):
+                    self.end_macro()
+            macroed(macro_name,old_macro_definition,cb)
+        else:
+            pronsole.pronsole.start_macro(self,macro_name,old_macro_definition)
     
     def catchprint(self,l):
         wx.CallAfter(self.logbox.AppendText,l)
@@ -831,6 +853,60 @@ class PronterWindow(wx.Frame,pronsole.pronsole):
                 self.printbtn.SetLabel("Print")
                 self.paused=0
             
+class macroed(wx.Frame):
+    """Really simple editor to edit macro definitions"""
+    def __init__(self,macro_name,definition,callback):
+        self.indent_chars = "  "
+        wx.Frame.__init__(self,None,title="macro %s" % macro_name)
+        self.callback = callback
+        self.panel=wx.Panel(self,-1)
+        titlesizer=wx.BoxSizer(wx.HORIZONTAL)
+        title = wx.StaticText(self.panel,-1,"  macro %s: "%macro_name)
+        title.SetFont(wx.Font(11,wx.NORMAL,wx.NORMAL,wx.BOLD))
+        titlesizer.Add(title,1)
+        self.okb = wx.Button(self.panel,-1,"Save")
+        self.okb.Bind(wx.EVT_BUTTON,self.save)
+        titlesizer.Add(self.okb)
+        self.cancelb = wx.Button(self.panel,-1,"Cancel")
+        self.cancelb.Bind(wx.EVT_BUTTON,self.close)
+        titlesizer.Add(self.cancelb)
+        topsizer=wx.BoxSizer(wx.VERTICAL)
+        topsizer.Add(titlesizer,0,wx.EXPAND)
+        self.e=wx.TextCtrl(self.panel,style=wx.TE_MULTILINE+wx.HSCROLL,size=(200,200))
+        self.e.SetValue(self.unindent(definition))
+        topsizer.Add(self.e,1,wx.ALL+wx.EXPAND)
+        self.panel.SetSizer(topsizer)
+        topsizer.Layout()
+        topsizer.Fit(self)
+        self.Show()
+    def save(self,ev):
+        self.Close()
+        self.callback(self.reindent(self.e.GetValue()))
+    def close(self,ev):
+        self.Close()
+    def unindent(self,text):
+        import re
+        self.indent_chars = text[:len(text)-len(text.lstrip())]
+        unindented = ""
+        lines = re.split(r"(?:\r\n?|\n)",text)
+        #print lines
+        if len(lines) <= 1:
+            return text
+        for line in lines:
+            if line.startswith(self.indent_chars):
+                unindented += line[len(self.indent_chars):] + "\n"
+            else:
+                unindented += line + "\n"
+        return unindented
+    def reindent(self,text):
+        import re
+        lines = re.split(r"(?:\r\n?|\n)",text)
+        if len(lines) <= 1:
+            return text
+        reindented = ""
+        for line in lines:
+            reindented += self.indent_chars + line + "\n"
+        return reindented
         
         
 if __name__ == '__main__':