diff --git a/language_packs/data/en_mathematics_logic_v1/manifest.json b/language_packs/data/en_mathematics_logic_v1/manifest.json
index 727b39f4..b4944ed7 100644
--- a/language_packs/data/en_mathematics_logic_v1/manifest.json
+++ b/language_packs/data/en_mathematics_logic_v1/manifest.json
@@ -11,6 +11,6 @@
   "gate_engaged": true,
   "oov_policy": "tagged_fallback",
   "glosses_checksum": "b7d6e1db7469f9fb81d4e376776c790d6511ba7ee44fdb4a7ac58ec65366103a",
-  "definitional_layer": true,
+  "definitional_layer": false,
   "provenance": "adr-0090:domain_seed:2026-05-21"
 }
diff --git a/language_packs/data/en_physics_v1/manifest.json b/language_packs/data/en_physics_v1/manifest.json
index 37e5c3a2..6d82d316 100644
--- a/language_packs/data/en_physics_v1/manifest.json
+++ b/language_packs/data/en_physics_v1/manifest.json
@@ -11,6 +11,6 @@
   "gate_engaged": true,
   "oov_policy": "tagged_fallback",
   "glosses_checksum": "2d813897f06e0ac777044094a788710454e0e66d4a3725c0ed2436edbfc67830",
-  "definitional_layer": true,
+  "definitional_layer": false,
   "provenance": "adr-0090:domain_seed:2026-05-21"
 }
diff --git a/language_packs/data/en_systems_software_v1/manifest.json b/language_packs/data/en_systems_software_v1/manifest.json
index c56c85a2..449e1a50 100644
--- a/language_packs/data/en_systems_software_v1/manifest.json
+++ b/language_packs/data/en_systems_software_v1/manifest.json
@@ -11,6 +11,6 @@
   "gate_engaged": true,
   "oov_policy": "tagged_fallback",
   "glosses_checksum": "189a8686c02ac7a0801ef4d32fd52e551b5b88a1937d1e4efa7d449d16e74833",
-  "definitional_layer": true,
+  "definitional_layer": false,
   "provenance": "adr-0090:domain_seed:2026-05-21"
 }