diff --git a/.gitmodules b/.gitmodules
index 5ece87098e..8d603cc359 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/junwang-noaa/fv3atm
+  branch = checksum_io
 [submodule "WW3"]
   path = WW3
   url = https://github.com/NOAA-EMC/WW3
diff --git a/FV3 b/FV3
index 280eeefefa..3f3f0a2858 160000
--- a/FV3
+++ b/FV3
@@ -1 +1 @@
-Subproject commit 280eeefefa087123070cbb8e7d36857d80d078c3
+Subproject commit 3f3f0a2858d8418ab6eb3f893ee530b77a69d89d