diff --git a/sql/042-expand-verification-method.sql b/sql/042-expand-verification-method.sql
new file mode 100644
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+++ b/sql/042-expand-verification-method.sql
@@ -0,0 +1,17 @@
+-- Migration 042 — Expand compatibility.verification_method CHECK constraint
+-- Adds vendor_compat (Flexoptix search API match) and spec_match (form-factor inference)
+-- to the existing set of allowed verification methods.
+
+ALTER TABLE compatibility
+  DROP CONSTRAINT IF EXISTS compatibility_verification_method_check;
+
+ALTER TABLE compatibility
+  ADD CONSTRAINT compatibility_verification_method_check
+  CHECK (verification_method IN (
+    'tested',
+    'vendor_matrix',
+    'vendor_compat',
+    'spec_match',
+    'datasheet',
+    'community'
+  ));