diff --git a/migrations/versions/20260410_0009_portfolio_comments_table.py b/migrations/versions/20260410_0009_portfolio_comments_table.py
index 0a238a8..b57d3ab 100644
--- a/migrations/versions/20260410_0009_portfolio_comments_table.py
+++ b/migrations/versions/20260410_0009_portfolio_comments_table.py
@@ -18,22 +18,28 @@ depends_on = None
 
 
 def upgrade() -> None:
-    op.create_table(
-        "portfolio_comments",
-        sa.Column("id", sa.Text(), primary_key=True),
-        sa.Column("portfolio_id", sa.Text(), nullable=False),
-        sa.Column("content", sa.Text(), nullable=False),
-        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.text("NOW()")),
-        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.text("NOW()")),
+    # `ensure_schema()` can create this table ahead of Alembic on already-running
+    # environments, so this migration must be safe to re-apply.
+    op.execute(
+        """
+        CREATE TABLE IF NOT EXISTS portfolio_comments (
+            id TEXT NOT NULL,
+            portfolio_id TEXT NOT NULL,
+            content TEXT NOT NULL,
+            created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW() NOT NULL,
+            updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW() NOT NULL,
+            PRIMARY KEY (id)
+        )
+        """
     )
-    op.create_index(
-        "idx_portfolio_comments_portfolio_created",
-        "portfolio_comments",
-        ["portfolio_id", sa.text("created_at DESC")],
-        unique=False,
+    op.execute(
+        """
+        CREATE INDEX IF NOT EXISTS idx_portfolio_comments_portfolio_created
+        ON portfolio_comments (portfolio_id, created_at DESC)
+        """
     )
 
 
 def downgrade() -> None:
-    op.drop_index("idx_portfolio_comments_portfolio_created", table_name="portfolio_comments")
-    op.drop_table("portfolio_comments")
+    op.execute("DROP INDEX IF EXISTS idx_portfolio_comments_portfolio_created")
+    op.execute("DROP TABLE IF EXISTS portfolio_comments")