diff --git a/Dockerfile.test b/Dockerfile.test
index 2846d2e..89c37c9 100644
--- a/Dockerfile.test
+++ b/Dockerfile.test
@@ -11,4 +11,3 @@ COPY . .
 RUN --mount=type=secret,id=test_db_url,required=true \
     export TEST_DATABASE_URL="$(cat /run/secrets/test_db_url)" && \
     cargo test -p db --test ai_credits --test ai_credits_reaper -- --test-threads=1
-# re-run: nxtgauge_test now has seed data (free plan)
diff --git a/crates/db/migrations/20260813000000_fix_ai_credits_timestamp_types.down.sql b/crates/db/migrations/20260813000000_fix_ai_credits_timestamp_types.down.sql
new file mode 100644
index 0000000..add65ed
--- /dev/null
+++ b/crates/db/migrations/20260813000000_fix_ai_credits_timestamp_types.down.sql
@@ -0,0 +1,20 @@
+BEGIN;
+
+ALTER TABLE ai_usage_logs
+    ALTER COLUMN created_at TYPE TIMESTAMP USING created_at AT TIME ZONE 'UTC';
+
+ALTER TABLE ai_feature_costs
+    ALTER COLUMN created_at TYPE TIMESTAMP USING created_at AT TIME ZONE 'UTC',
+    ALTER COLUMN updated_at TYPE TIMESTAMP USING updated_at AT TIME ZONE 'UTC';
+
+ALTER TABLE user_ai_subscriptions
+    ALTER COLUMN current_period_start TYPE TIMESTAMP USING current_period_start AT TIME ZONE 'UTC',
+    ALTER COLUMN current_period_end   TYPE TIMESTAMP USING current_period_end   AT TIME ZONE 'UTC',
+    ALTER COLUMN created_at           TYPE TIMESTAMP USING created_at           AT TIME ZONE 'UTC',
+    ALTER COLUMN updated_at           TYPE TIMESTAMP USING updated_at           AT TIME ZONE 'UTC';
+
+ALTER TABLE ai_plans
+    ALTER COLUMN created_at TYPE TIMESTAMP USING created_at AT TIME ZONE 'UTC',
+    ALTER COLUMN updated_at TYPE TIMESTAMP USING updated_at AT TIME ZONE 'UTC';
+
+COMMIT;
diff --git a/crates/db/migrations/20260813000000_fix_ai_credits_timestamp_types.up.sql b/crates/db/migrations/20260813000000_fix_ai_credits_timestamp_types.up.sql
new file mode 100644
index 0000000..ef2e09c
--- /dev/null
+++ b/crates/db/migrations/20260813000000_fix_ai_credits_timestamp_types.up.sql
@@ -0,0 +1,37 @@
+-- Fix ai_plans/user_ai_subscriptions/ai_feature_costs/ai_usage_logs timestamp
+-- columns: they were created (by whatever earlier, pre-20260703210000
+-- mechanism made these tables) as `TIMESTAMP` (no timezone), but
+-- crates/db/src/models/ai_credits.rs maps every one of these to
+-- `DateTime<Utc>`, which sqlx requires the column to be `TIMESTAMPTZ` for.
+-- Discovered via crates/db/tests/ai_credits.rs failing with:
+--   ColumnDecode { ... "TIMESTAMPTZ" is not compatible with SQL type "TIMESTAMP" }
+-- This is a real, live bug, not just a test-setup gap: any production code
+-- path that SELECTs current_period_start/current_period_end (or any of the
+-- other columns below) via these structs would hit the same decode error.
+--
+-- `AT TIME ZONE 'UTC'` reinterprets the existing naive values as UTC wall-clock
+-- time when adding the zone (the correct, lossless conversion given every
+-- write path uses NOW()/DEFAULT NOW() with no other timezone handling
+-- anywhere in this codebase) rather than converting through the session's
+-- local timezone.
+
+BEGIN;
+
+ALTER TABLE ai_plans
+    ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC',
+    ALTER COLUMN updated_at TYPE TIMESTAMPTZ USING updated_at AT TIME ZONE 'UTC';
+
+ALTER TABLE user_ai_subscriptions
+    ALTER COLUMN current_period_start TYPE TIMESTAMPTZ USING current_period_start AT TIME ZONE 'UTC',
+    ALTER COLUMN current_period_end   TYPE TIMESTAMPTZ USING current_period_end   AT TIME ZONE 'UTC',
+    ALTER COLUMN created_at           TYPE TIMESTAMPTZ USING created_at           AT TIME ZONE 'UTC',
+    ALTER COLUMN updated_at           TYPE TIMESTAMPTZ USING updated_at           AT TIME ZONE 'UTC';
+
+ALTER TABLE ai_feature_costs
+    ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC',
+    ALTER COLUMN updated_at TYPE TIMESTAMPTZ USING updated_at AT TIME ZONE 'UTC';
+
+ALTER TABLE ai_usage_logs
+    ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC';
+
+COMMIT;