diff --git a/setup.py b/setup.py
index 525a1138c..bda286d5c 100644
--- a/setup.py
+++ b/setup.py
@@ -25,11 +25,11 @@
     # The core 'install_requires' should only be things
     # which are needed for the main editor to function.
     #
-    "PyQt5==5.15.10"
+    "PyQt5==5.13.2"
     + ';"arm" not in platform_machine and "aarch" not in platform_machine',
     "QScintilla==2.14.1"
     + ';"arm" not in platform_machine and "aarch" not in platform_machine',
-    "PyQtChart==5.15.6"
+    "PyQtChart==5.13.1"
     + ';"arm" not in platform_machine and "aarch" not in platform_machine',
     # ipykernel has to be < v6 for macOS 10.13 compatibility (v6 depends on
     # debugpy package), v5.5.6 resolves issue ipython/ipykernel#759.