diff --git a/CHANGELOG.md b/CHANGELOG.md
index cd6bfdf1..b5e22abb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,10 +11,13 @@ Notable differences from version 1.1.2.
 
 ### Changed
 
+- Update wxpython to 4.1.1, and remove incompatible align flags.
+
 ### Deprecated
 
 ### Removed
 
 ### Fixed
 
--  Incompatible conversion between bytes and str from py2 to py3.
+- Incompatible conversion between bytes and str from py2 to py3.
+- Replace the deprecated `Thread.isAlive()` with `Thread.is_alive()`.
diff --git a/setup.py b/setup.py
index fc0e0d32..47dfe63b 100755
--- a/setup.py
+++ b/setup.py
@@ -15,7 +15,7 @@
 
 # Use this version when git data are not available, like in git zip archive.
 # Update when tagging a new release.
-FALLBACK_VERSION = '1.4.3'
+FALLBACK_VERSION = '1.4.6'
 
 # determine if we run with Python 3.
 PY3 = (sys.version_info[0] == 3)
diff --git a/src/diffpy/pdfgui/control/fitting.py b/src/diffpy/pdfgui/control/fitting.py
index 7e42b1dc..a85bddce 100644
--- a/src/diffpy/pdfgui/control/fitting.py
+++ b/src/diffpy/pdfgui/control/fitting.py
@@ -553,7 +553,7 @@ def isThreadRunning(self):
 
         return: True if running, False otherwise
         """
-        return self.thread is not None and self.thread.isAlive()
+        return self.thread is not None and self.thread.is_alive()
 
     def join(self):
         """wait for current fitting to finish"""
diff --git a/src/diffpy/pdfgui/control/pdfguicontrol.py b/src/diffpy/pdfgui/control/pdfguicontrol.py
index 5f838a5f..8d74c312 100644
--- a/src/diffpy/pdfgui/control/pdfguicontrol.py
+++ b/src/diffpy/pdfgui/control/pdfguicontrol.py
@@ -159,7 +159,7 @@ def exit(self):
         """exit when program finished
         """
         self.close()
-        if self.queueManager.isAlive():
+        if self.queueManager.is_alive():
             self.queueManager.running = False
 
     def newFitting(self, name, position=None):