diff --git a/.gitmodules b/.gitmodules
index 8b5b737335..47c91d4b13 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,7 +1,9 @@
 [submodule "FV3"]
   path = FV3
-  url = https://github.com/NOAA-EMC/fv3atm
-  branch = develop
+  #url = https://github.com/NOAA-EMC/fv3atm
+  #branch = develop
+  url = https://github.com/climbfuji/fv3atm
+  branch = remove_optional_arguments_from_ccpp
 [submodule "NEMS"]
   path = NEMS
   url = https://github.com/NOAA-EMC/NEMS
diff --git a/FV3 b/FV3
index 4214e6d23d..8c3d83c3d8 160000
--- a/FV3
+++ b/FV3
@@ -1 +1 @@
-Subproject commit 4214e6d23d63af231521b1a6064d34a967dfd87c
+Subproject commit 8c3d83c3d88fedb27adec963c643634117fe821c