diff --git a/.gitmodules b/.gitmodules
index 91761e36..a568c00e 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -5,7 +5,7 @@
 [submodule "providers/openfeature-provider-flagd/test-harness"]
 	path = providers/openfeature-provider-flagd/openfeature/test-harness
 	url = git@github.com:open-feature/flagd-testbed.git
-	branch = v0.5.21
+	branch = v1.4.0
 [submodule "providers/openfeature-provider-flagd/spec"]
 	path = providers/openfeature-provider-flagd/openfeature/spec
 	url = https://github.com/open-feature/spec
diff --git a/providers/openfeature-provider-flagd/openfeature/test-harness b/providers/openfeature-provider-flagd/openfeature/test-harness
index 8931c864..9cc25e95 160000
--- a/providers/openfeature-provider-flagd/openfeature/test-harness
+++ b/providers/openfeature-provider-flagd/openfeature/test-harness
@@ -1 +1 @@
-Subproject commit 8931c8645b8600e251d5e3ebbad42dff8ce4c78e
+Subproject commit 9cc25e95301881032a1a45eb5cb7cb6684071edf