diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
index 4f99101..bff5179 100644
--- a/pg_ivm--1.10--1.11.sql
+++ b/pg_ivm--1.10--1.11.sql
@@ -25,17 +25,25 @@ $$
 DECLARE
 	old_search_path text;
 BEGIN
-	-- Empty search path so that get_immv_def returns a fully-qualified query.
-	SELECT setting INTO old_search_path FROM pg_catalog.pg_settings
-		WHERE name = 'search_path';
-	SET search_path = '';
+	-- Only need to refresh query strings if an object is renamed.
+	-- As a rough heuristic, check if this is an ALTER command.
+	IF tg_tag LIKE 'ALTER %' THEN
+		-- Empty search path so that get_immv_def returns a fully-qualified query.
+		SELECT setting INTO old_search_path FROM pg_catalog.pg_settings
+			WHERE name = 'search_path';
+		SET search_path = '';
 
-	UPDATE pgivm.pg_ivm_immv SET querystring = pgivm.get_immv_def(immvrelid);
+		UPDATE pgivm.pg_ivm_immv SET querystring = pgivm.get_immv_def(immvrelid);
 
-	-- Reset search path to the original value.
-	IF old_search_path != '' AND old_search_path != '""' THEN
-		EXECUTE format('SET search_path = %s', old_search_path);
+		-- Reset search path to the original value.
+		IF old_search_path != '' AND old_search_path != '""' THEN
+			EXECUTE format('SET search_path = %s', old_search_path);
+		END IF;
 	END IF;
+EXCEPTION
+	WHEN internal_error THEN
+		RAISE WARNING 'pg_ivm could not refresh the pg_ivm_immv query strings.'
+			USING HINT = 'Please recreate your IMMVs using pgivm.recreate_all_immvs().';
 END
 $$;