diff --git a/src/test/modules/injection_points/injection_stats_fixed.c b/src/test/modules/injection_points/injection_stats_fixed.c
index bc54c79d190b..74c35fcbfa71 100644
--- a/src/test/modules/injection_points/injection_stats_fixed.c
+++ b/src/test/modules/injection_points/injection_stats_fixed.c
@@ -152,6 +152,8 @@ pgstat_report_inj_fixed(uint32 numattach,
 
 	stats_shmem = pgstat_get_custom_shmem_data(PGSTAT_KIND_INJECTION_FIXED);
 
+	LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE);
+
 	pgstat_begin_changecount_write(&stats_shmem->changecount);
 	stats_shmem->stats.numattach += numattach;
 	stats_shmem->stats.numdetach += numdetach;
@@ -159,6 +161,8 @@ pgstat_report_inj_fixed(uint32 numattach,
 	stats_shmem->stats.numcached += numcached;
 	stats_shmem->stats.numloaded += numloaded;
 	pgstat_end_changecount_write(&stats_shmem->changecount);
+
+	LWLockRelease(&stats_shmem->lock);
 }
 
 /*