diff --git a/crt/CMakeLists.txt b/crt/CMakeLists.txt
index a88a846c..e49071b5 100644
--- a/crt/CMakeLists.txt
+++ b/crt/CMakeLists.txt
@@ -61,6 +61,7 @@ if(UNIX AND NOT APPLE)
         SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/s2n
         CMAKE_ARGUMENTS
             -DUNSAFE_TREAT_WARNINGS_AS_ERRORS=OFF
+            -DBUILD_TESTING=OFF
     )
 endif()
 
diff --git a/crt/aws-c-io b/crt/aws-c-io
index 67b07464..8f85d226 160000
--- a/crt/aws-c-io
+++ b/crt/aws-c-io
@@ -1 +1 @@
-Subproject commit 67b0746407deefd2f3963d9c191fda31cc45f985
+Subproject commit 8f85d22662c9eefadd2ad683d29206a82970aa07