diff --git a/.gitmodules b/.gitmodules
index ad5fe10a..29c5e5e5 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -8,4 +8,4 @@
 [submodule "providers/openfeature-provider-flagd/openfeature/test-harness"]
 	path = providers/openfeature-provider-flagd/openfeature/test-harness
 	url = https://github.com/open-feature/flagd-testbed.git
-	branch = v2.11.1
+	branch = v2.15.9
diff --git a/providers/openfeature-provider-flagd/openfeature/test-harness b/providers/openfeature-provider-flagd/openfeature/test-harness
index fe68e031..ecb3d096 160000
--- a/providers/openfeature-provider-flagd/openfeature/test-harness
+++ b/providers/openfeature-provider-flagd/openfeature/test-harness
@@ -1 +1 @@
-Subproject commit fe68e0310fd817a8f9bc1e2559f2277fed3aed34
+Subproject commit ecb3d096c82c52424eeb545cf481f2f1d4794d21