diff --git a/expected/plpgsql_check_passive.out b/expected/plpgsql_check_passive.out
index dbbc7d2..473a3c2 100644
--- a/expected/plpgsql_check_passive.out
+++ b/expected/plpgsql_check_passive.out
@@ -353,3 +353,9 @@ end;
 $$ language plpgsql;
 call proc_test();
 drop procedure proc_test();
+-- should not to crash
+set plpgsql_check.mode = 'fresh_start';
+do $$
+begin
+end;
+$$;
diff --git a/expected/plpgsql_check_passive_1.out b/expected/plpgsql_check_passive_1.out
index 31f45c9..d9c9b6e 100644
--- a/expected/plpgsql_check_passive_1.out
+++ b/expected/plpgsql_check_passive_1.out
@@ -350,3 +350,9 @@ end;
 $$ language plpgsql;
 call proc_test();
 drop procedure proc_test();
+-- should not to crash
+set plpgsql_check.mode = 'fresh_start';
+do $$
+begin
+end;
+$$;
diff --git a/sql/plpgsql_check_passive.sql b/sql/plpgsql_check_passive.sql
index 094a52e..f627802 100644
--- a/sql/plpgsql_check_passive.sql
+++ b/sql/plpgsql_check_passive.sql
@@ -325,3 +325,10 @@ $$ language plpgsql;
 call proc_test();
 
 drop procedure proc_test();
+
+-- should not to crash
+set plpgsql_check.mode = 'fresh_start';
+do $$
+begin
+end;
+$$;
diff --git a/src/check_function.c b/src/check_function.c
index 5be61b7..c0a2427 100644
--- a/src/check_function.c
+++ b/src/check_function.c
@@ -1375,6 +1375,9 @@ plpgsql_check_is_checked(PLpgSQL_function *func)
 {
 	plpgsql_check_HashEnt *hentry;
 
+	if (!func->fn_hashkey)
+		return false;
+
 	hentry = (plpgsql_check_HashEnt *) hash_search(plpgsql_check_HashTable,
 											 (void *) func->fn_hashkey,
 											 HASH_FIND,