diff --git a/backend-rust/src/migrations/m0002-block-cumulative-fin-time-index.sql b/backend-rust/src/migrations/m0002-block-cumulative-fin-time-index.sql
index 2f9bc9ea..0d0fe686 100644
--- a/backend-rust/src/migrations/m0002-block-cumulative-fin-time-index.sql
+++ b/backend-rust/src/migrations/m0002-block-cumulative-fin-time-index.sql
@@ -3,6 +3,8 @@
 CREATE INDEX blocks_height_null_cumulative_finalization_time ON blocks (height)
     WHERE blocks.cumulative_finalization_time IS NULL
     AND blocks.finalization_time IS NOT NULL;
+-- blocks_hash_gin_trgm_idx index does not suppport char
+ALTER TABLE blocks ALTER COLUMN hash SET DATA TYPE VARCHAR(64);
 -- Used to efficiently perform partial string matching on the `hash` column,
 -- allowing fast lookups when searching for blocks by their hash prefix using `LIKE`.
 CREATE INDEX blocks_hash_gin_trgm_idx ON blocks USING gin(hash gin_trgm_ops);