diff --git a/db/post_migrate/20251215180743_validate_not_null_constraint_on_spam_logs_for_user_id.rb b/db/post_migrate/20251215180743_validate_not_null_constraint_on_spam_logs_for_user_id.rb
new file mode 100644
index 0000000000000000000000000000000000000000..803360cfb13e984376502d2179b91b00afbbd7a4
--- /dev/null
+++ b/db/post_migrate/20251215180743_validate_not_null_constraint_on_spam_logs_for_user_id.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class ValidateNotNullConstraintOnSpamLogsForUserId < Gitlab::Database::Migration[2.3]
+  milestone '18.8'
+
+  def up
+    validate_not_null_constraint :spam_logs, :user_id, constraint_name: "check_56d1d910ee"
+  end
+
+  def down
+    # no-op
+  end
+end
diff --git a/db/post_migrate/20251215180745_validate_foreign_key_constraint_on_spam_logs_for_user_id.rb b/db/post_migrate/20251215180745_validate_foreign_key_constraint_on_spam_logs_for_user_id.rb
new file mode 100644
index 0000000000000000000000000000000000000000..88ab565796afa1814b172d0bf9b6ce8b786b411a
--- /dev/null
+++ b/db/post_migrate/20251215180745_validate_foreign_key_constraint_on_spam_logs_for_user_id.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class ValidateForeignKeyConstraintOnSpamLogsForUserId < Gitlab::Database::Migration[2.3]
+  milestone '18.8'
+
+  def up
+    validate_foreign_key :spam_logs, :user_id, name: 'fk_1cb83308b1'
+  end
+
+  def down
+    # no-op
+  end
+end
diff --git a/db/schema_migrations/20251215180743 b/db/schema_migrations/20251215180743
new file mode 100644
index 0000000000000000000000000000000000000000..7b05ea279c09ce3d3c4d16f7b375f3850db1510e
--- /dev/null
+++ b/db/schema_migrations/20251215180743
@@ -0,0 +1 @@
+2e56a8a912918b634b92153d1ab852a4b137c61088db2a790ab25bd76a916d02
\ No newline at end of file
diff --git a/db/schema_migrations/20251215180745 b/db/schema_migrations/20251215180745
new file mode 100644
index 0000000000000000000000000000000000000000..0b9e9cb83aa6483f11175656ac3f030e8fd1984e
--- /dev/null
+++ b/db/schema_migrations/20251215180745
@@ -0,0 +1 @@
+25b9f50f211266f92b03e21d0d8f83bcb9cfe6730e24cd7c466995060b83c769
\ No newline at end of file
diff --git a/db/structure.sql b/db/structure.sql
index 6746648605376e984366abac822589d883ff7cbb..47a43bcd3f7490f3f8ac7fdbb687202c629b8151 100644
--- a/db/structure.sql
+++ b/db/structure.sql
@@ -27652,7 +27652,8 @@ CREATE TABLE spam_logs (
     submitted_as_ham boolean DEFAULT false NOT NULL,
     recaptcha_verified boolean DEFAULT false NOT NULL,
     target_id bigint,
-    organization_id bigint
+    organization_id bigint,
+    CONSTRAINT check_56d1d910ee CHECK ((user_id IS NOT NULL))
 );
 
 CREATE SEQUENCE spam_logs_id_seq
@@ -35075,9 +35076,6 @@ ALTER TABLE user_details
 ALTER TABLE diff_note_positions
     ADD CONSTRAINT check_4c86140f48 CHECK ((namespace_id IS NOT NULL)) NOT VALID;
 
-ALTER TABLE spam_logs
-    ADD CONSTRAINT check_56d1d910ee CHECK ((user_id IS NOT NULL)) NOT VALID;
-
 ALTER TABLE ONLY instance_type_ci_runners
     ADD CONSTRAINT check_5c34a3c1db UNIQUE (id);
 
@@ -50155,7 +50153,7 @@ ALTER TABLE ONLY approval_policy_rule_project_links
     ADD CONSTRAINT fk_1c78796d52 FOREIGN KEY (approval_policy_rule_id) REFERENCES approval_policy_rules(id) ON DELETE CASCADE;
 
 ALTER TABLE ONLY spam_logs
-    ADD CONSTRAINT fk_1cb83308b1 FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE NOT VALID;
+    ADD CONSTRAINT fk_1cb83308b1 FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE;
 
 ALTER TABLE ONLY issue_links
     ADD CONSTRAINT fk_1cce06b868 FOREIGN KEY (namespace_id) REFERENCES namespaces(id) ON DELETE CASCADE;
diff --git a/ee/spec/lib/gitlab/database/desired_sharding_key_spec.rb b/ee/spec/lib/gitlab/database/desired_sharding_key_spec.rb
index d115649ae05309e7114e9ba43eb253bf7b723c1a..fff75fa656e7f12e06a9cf635dc52c4ee250fc23 100644
--- a/ee/spec/lib/gitlab/database/desired_sharding_key_spec.rb
+++ b/ee/spec/lib/gitlab/database/desired_sharding_key_spec.rb
@@ -23,7 +23,6 @@
       'design_management_versions.issue_id', # https://gitlab.com/gitlab-org/gitlab/-/issues/461330
       'requirements_management_test_reports.issue_id', # https://gitlab.com/gitlab-org/gitlab/-/issues/383031
       # We nullify the FK once the parent is deleted and remove entries using a cleanup worker.
-      'spam_logs.user_id',
       'packages_nuget_symbols.package_id'
     ]
   end