diff --git a/crt/aws-c-cal b/crt/aws-c-cal
index 094ea6757..9ab6f96e5 160000
--- a/crt/aws-c-cal
+++ b/crt/aws-c-cal
@@ -1 +1 @@
-Subproject commit 094ea67577fcd725b5c19d2ee08c2b7c8b286c24
+Subproject commit 9ab6f96e5aba10b2e337c51e62d9400f001cfe0c
diff --git a/crt/aws-c-http b/crt/aws-c-http
index 0426a065b..f686b89d8 160000
--- a/crt/aws-c-http
+++ b/crt/aws-c-http
@@ -1 +1 @@
-Subproject commit 0426a065b77e99ce8dbbe2e89f6e9fae35840728
+Subproject commit f686b89d8c3f500387db10a7f1614eadebf0b0ff
diff --git a/crt/aws-c-s3 b/crt/aws-c-s3
index 76f49fbfa..303d62cfc 160000
--- a/crt/aws-c-s3
+++ b/crt/aws-c-s3
@@ -1 +1 @@
-Subproject commit 76f49fbfa9deabd464842900744fad10a44314b4
+Subproject commit 303d62cfc05cfb2807cacf7fe1b3721dfe8ad216
diff --git a/crt/aws-c-sdkutils b/crt/aws-c-sdkutils
index 399f5253c..e3c23f4ac 160000
--- a/crt/aws-c-sdkutils
+++ b/crt/aws-c-sdkutils
@@ -1 +1 @@
-Subproject commit 399f5253c42c673091dca131bcf51f20f3de194c
+Subproject commit e3c23f4aca31d9e66df25827645f72cbcbfb657a
diff --git a/crt/aws-lc b/crt/aws-lc
index d72b5bb66..b40498737 160000
--- a/crt/aws-lc
+++ b/crt/aws-lc
@@ -1 +1 @@
-Subproject commit d72b5bb66c9fd81f6281ad25a642112e08ba8662
+Subproject commit b40498737348fee436a65e2a4badfb392acca36d
diff --git a/crt/s2n b/crt/s2n
index 785596b96..65455a2c9 160000
--- a/crt/s2n
+++ b/crt/s2n
@@ -1 +1 @@
-Subproject commit 785596b9694d7e12274afea9f42b8216a07102da
+Subproject commit 65455a2c93370b6878ee04efb41c51409cf807db
diff --git a/elasticurl.py b/elasticurl.py
index a5fb5dc1d..04744e507 100755
--- a/elasticurl.py
+++ b/elasticurl.py
@@ -233,7 +233,10 @@ def on_incoming_body(http_stream, chunk, **kwargs):
 if url.query:
     request.path += '?' + url.query
 
-request.headers.add('host', hostname)
+if connection.version == http.HttpVersion.Http2:
+    request.headers.add(':authority', hostname)
+else:
+    request.headers.add('host', hostname)
 request.headers.add('user-agent', 'elasticurl.py 1.0, Powered by the AWS Common Runtime.')
 
 if data_len != 0: