diff --git a/changelog.d/fix-ss-state-backend-core-3348.fixed.md b/changelog.d/fix-ss-state-backend-core-3348.fixed.md
new file mode 100644
index 00000000000..5039c8d4ec6
--- /dev/null
+++ b/changelog.d/fix-ss-state-backend-core-3348.fixed.md
@@ -0,0 +1 @@
+Give the Social Security input state-machine test's Core backend the holder-rebinding method that policyengine-core 3.34.8's `apply_reform` calls, which had made the test fail on every pull request.
diff --git a/policyengine_us/tests/core/_social_security_state_backend.py b/policyengine_us/tests/core/_social_security_state_backend.py
index 04d6f7d1550..cf4fd10caa6 100644
--- a/policyengine_us/tests/core/_social_security_state_backend.py
+++ b/policyengine_us/tests/core/_social_security_state_backend.py
@@ -621,6 +621,10 @@ def load(self):
             "clone",
             "get_branch",
             "apply_reform",
+            # From Core 3.34.8 apply_reform rebinds holders to the reformed
+            # system, and each existing branch to its own, before replaying
+            # inputs.
+            "_bind_to_tax_benefit_system",
             "_invalidate_all_caches",
             "drop_computed_arrays",
             "extract_person",