diff --git a/async_postgres/pg_connection/lifecycle.nim b/async_postgres/pg_connection/lifecycle.nim
index 775fe44..712127b 100644
--- a/async_postgres/pg_connection/lifecycle.nim
+++ b/async_postgres/pg_connection/lifecycle.nim
@@ -371,7 +371,7 @@ proc connectToHost*(
     # Discover extension type OIDs (hstore, etc.)
     conn.state = csBusy
     await conn.sendMsg(
-      encodeQuery("SELECT oid, typarray FROM pg_type WHERE typname = 'hstore' LIMIT 1")
+      encodeQuery("SELECT oid, typarray FROM pg_type WHERE oid = to_regtype('hstore')")
     )
     block discoverLoop:
       while true:
diff --git a/async_postgres/pg_connection/types.nim b/async_postgres/pg_connection/types.nim
index 74205fa..6769aaf 100644
--- a/async_postgres/pg_connection/types.nim
+++ b/async_postgres/pg_connection/types.nim
@@ -215,7 +215,11 @@ type
       ## current cache size). Flushed by ``flushPendingStmtCloses`` at the
       ## start of the next Extended Query send phase so the leak is bounded
       ## to the gap until the next operation.
-    hstoreOid*: int32 ## Dynamic OID for hstore extension type; 0 if not available
+    hstoreOid*: int32
+      ## Dynamic OID for the hstore extension type; 0 if not available.
+      ## Resolved once at connect time via ``to_regtype('hstore')``, which
+      ## follows the connection's ``search_path`` at that moment. Later
+      ## ``SET search_path`` changes do not refresh this value.
     hstoreArrayOid*: int32 ## Dynamic OID for hstore[] array; 0 if not available
     heldSessionLocks*: int
       ## Count of session-level `pg_advisory_lock` acquires through the typed
diff --git a/tests/test_e2e.nim b/tests/test_e2e.nim
index 1f90ac0..9de86f8 100644
--- a/tests/test_e2e.nim
+++ b/tests/test_e2e.nim
@@ -10519,6 +10519,25 @@ suite "E2E: Numeric / binary / JSON array types":
 
     waitFor t()
 
+  test "hstore OID discovery respects search_path":
+    # to_regtype('hstore') must return NULL — and hstoreOid must stay 0 —
+    # when the connection's startup search_path excludes the schema where
+    # hstore is installed. Guards against regressing to a typname-only
+    # lookup that would resolve hstore regardless of search_path.
+    proc t() {.async.} =
+      let setup = await connect(plainConfig())
+      discard await setup.simpleQuery("CREATE EXTENSION IF NOT EXISTS hstore;")
+      await setup.close()
+
+      var cfg = plainConfig()
+      cfg.extraParams = @[("search_path", "pg_catalog")]
+      let conn = await connect(cfg)
+      doAssert conn.hstoreOid == 0
+      doAssert conn.hstoreArrayOid == 0
+      await conn.close()
+
+    waitFor t()
+
   test "bytea array roundtrip":
     proc t() {.async.} =
       let conn = await connect(plainConfig())