diff --git a/service/grails-app/migrations/correct-gin-indices-pre-quesnalia.groovy b/service/grails-app/migrations/correct-gin-indices-pre-quesnalia.groovy
new file mode 100644
index 0000000..a0a9794
--- /dev/null
+++ b/service/grails-app/migrations/correct-gin-indices-pre-quesnalia.groovy
@@ -0,0 +1,57 @@
+databaseChangeLog = {
+  /* GIN Indexes have been added in update-mod-licenses-5-1.groovy
+   * These can cause issues when the underlying data passes a certain limit
+   * due to trigram operator not being used and the postgres token size growing
+   *
+   * It is a little unorthodox, however these index creations are conditional on
+   * "CREATE IF NOT EXISTS". We will make use of that to insert indices on those
+   * fields _before_ they are set up by upgrading/new implementors. For any tenants
+   * who already managed to upgrade, these new changesets will be ignored, but it
+   * it _recommended_ that an operational task be undertaken to bring those schemas
+   * in line with the indices in place on new instances of mod-agreements
+   */
+
+  // The first two of these shouldn't be impacted by the bug outlined in ERM-3387, but we bring them in line anyway
+  changeSet(author: "EFreestone (manual)", id: "2024-10-17-ERM-3387-quesnalia-1") {
+		preConditions (onFail: 'MARK_RAN', onError: 'WARN') {
+			not {
+				indexExists(tableName: 'alternate_name', columnNames: 'an_name')
+			}
+		}
+		// Gin indexes need to be done via scripting.
+		grailsChange {
+			change {
+				def cmd = "CREATE INDEX alternate_name_name_idx ON ${database.defaultSchemaName}.alternate_name USING gin (an_name gin_trgm_ops);".toString()
+				sql.execute(cmd);
+			}
+		}
+  }
+
+  changeSet(author: "EFreestone (manual)", id: "2024-10-17-ERM-3387-quesnalia-2") {
+		preConditions (onFail: 'MARK_RAN', onError: 'WARN') {
+			not {
+				indexExists(tableName: 'license', columnNames: 'lic_name')
+			}
+		}
+		grailsChange {
+			change {
+				def cmd = "CREATE INDEX license_name_idx ON ${database.defaultSchemaName}.license USING gin (lic_name gin_trgm_ops);".toString()
+				sql.execute(cmd);
+			}
+		}
+	}
+
+  changeSet(author: "EFreestone (manual)", id: "2024-10-17-ERM-3387-quesnalia-3") {
+		preConditions (onFail: 'MARK_RAN', onError: 'WARN') {
+			not {
+				indexExists(tableName: 'license', columnNames: 'lic_description')
+			}
+		}
+		grailsChange {
+			change {
+				def cmd = "CREATE INDEX license_description_idx ON ${database.defaultSchemaName}.license USING gin (lic_description gin_trgm_ops);".toString()
+				sql.execute(cmd);
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/service/grails-app/migrations/module-tenant-changelog.groovy b/service/grails-app/migrations/module-tenant-changelog.groovy
index 92fe103..5df9f3b 100644
--- a/service/grails-app/migrations/module-tenant-changelog.groovy
+++ b/service/grails-app/migrations/module-tenant-changelog.groovy
@@ -21,5 +21,6 @@ databaseChangeLog = {
   include file: 'wtk/hidden-appsetting.feat.groovy'
   include file: 'update-mod-license-4-2.groovy'
   include file: 'wtk/multi-value-custprops.feat.groovy'
+  include file: 'correct-gin-indices-pre-quesnalia.groovy'
   include file: 'update-mod-license-5-1.groovy'
 }