diff --git a/changes/ticket40485 b/changes/ticket40485
new file mode 100644
index 0000000000000000000000000000000000000000..849ee0719f21e77f276c8267a13571dc37c8b93e
--- /dev/null
+++ b/changes/ticket40485
@@ -0,0 +1,3 @@
+  o Testing (CI, chutney):
+    - Bump the data size that chutney transmit to 5MB in order to trigger flow
+      control and congestion window code. Closes ticket 40485.
diff --git a/scripts/ci/ci-driver.sh b/scripts/ci/ci-driver.sh
index d0b563a09bb2816e9a250841eecdc5407b4866cf..ff4881dd8e62e09fba3b26a2f22ba1755c30a8fd 100755
--- a/scripts/ci/ci-driver.sh
+++ b/scripts/ci/ci-driver.sh
@@ -449,6 +449,8 @@ if [[ "${CHUTNEY}" = "yes" ]]; then
     start_section "Chutney"
     export CHUTNEY_TOR_SANDBOX=0
     export CHUTNEY_ALLOW_FAILURES=2
+    # Send 5MB for every verify check.
+    export CHUTNEY_DATA_BYTES=5000000
     if runcmd make "${CHUTNEY_MAKE_TARGET}"; then
         hooray "Chutney tests have succeeded"
     else