diff --git a/GlyphConstruction.roboFontExt/info.plist b/GlyphConstruction.roboFontExt/info.plist
index 18d92e7..5a8a92f 100644
--- a/GlyphConstruction.roboFontExt/info.plist
+++ b/GlyphConstruction.roboFontExt/info.plist
@@ -30,8 +30,8 @@
 	<key>requiresVersionMinor</key>
 	<string>5</string>
 	<key>timeStamp</key>
-	<real>1594285837.2753458</real>
+	<real>1594289843.4766321</real>
 	<key>version</key>
-	<string>0.8.4</string>
+	<string>0.8.5</string>
 </dict>
 </plist>
diff --git a/GlyphConstruction.roboFontExt/lib/glyphConstructionController.py b/GlyphConstruction.roboFontExt/lib/glyphConstructionController.py
index 5a64f72..68da9e7 100644
--- a/GlyphConstruction.roboFontExt/lib/glyphConstructionController.py
+++ b/GlyphConstruction.roboFontExt/lib/glyphConstructionController.py
@@ -1,3 +1,4 @@
+import asyncio
 from fontTools.misc.py23 import *
 from AppKit import *
 import re
@@ -32,6 +33,15 @@
 from lib.scripting.codeEditor import CodeEditor
 import os
 
+
+def asyncTask(func):
+    
+    def wrapper(*args, **kwargs):
+        task = asyncio.create_task(func(*args, **kwargs))
+
+    return wrapper
+
+
 defaultKey = "com.typemytype.glyphBuilder"
 
 constructions = """# capitals
@@ -622,8 +632,12 @@ def unsubscribeFont(self):
             self.preview.set([])
             self.font.removeObserver(self, notification="Font.Changed")
             self.font = None
-
-    def constructionsCallback(self, sender, update=True):
+    
+    @asyncTask
+    async def constructionsCallback(self, sender, update=True):        
+        await asyncio.gather(self._constructionsCallback(sender, update))
+        
+    async def _constructionsCallback(self, sender, update=True): 
         if self.font is None:
             return
 
diff --git a/LibExtension/glyphConstructionController.py b/LibExtension/glyphConstructionController.py
index 5c3327d..e107e4f 100644
--- a/LibExtension/glyphConstructionController.py
+++ b/LibExtension/glyphConstructionController.py
@@ -1,3 +1,6 @@
+import asyncio
+import functools
+
 from fontTools.misc.py23 import *
 from AppKit import *
 import re
@@ -32,6 +35,23 @@
 from lib.scripting.codeEditor import CodeEditor
 import os
 
+
+def asyncTask(func):
+    
+    taskAttributeName = f"_{func.__name__}_autoCancelTask"
+    @functools.wraps(func)    
+    def createFuncTask(self, *args, **kwargs):
+        oldTask = getattr(self, taskAttributeName, None)
+        if oldTask is not None:
+            oldTask.cancel()
+        coro = func(self, *args, **kwargs)
+        task = asyncio.create_task(coro)
+        setattr(self, taskAttributeName, task)
+        return task
+        
+    return createFuncTask
+
+
 defaultKey = "com.typemytype.glyphBuilder"
 
 constructions = """# capitals
@@ -622,8 +642,12 @@ def unsubscribeFont(self):
             self.preview.set([])
             self.font.removeObserver(self, notification="Font.Changed")
             self.font = None
-
-    def constructionsCallback(self, sender, update=True):
+    
+    @asyncTask
+    async def constructionsCallback(self, sender, update=True):        
+        await asyncio.gather(self._constructionsCallback(sender, update))
+        
+    async def _constructionsCallback(self, sender, update=True): 
         if self.font is None:
             return
 
diff --git a/build-extension.py b/build-extension.py
index 2260a00..f1fd2ff 100644
--- a/build-extension.py
+++ b/build-extension.py
@@ -27,7 +27,7 @@
 B.name = "Glyph Construction"
 B.developer = 'Frederk Berlaen'
 B.developerURL = 'http://typemytype.com/'
-B.version = '0.8.4'
+B.version = '0.8.5'
 B.launchAtStartUp = True
 B.mainScript = 'glyphConstructionUIStartUp.py'
 B.html = True