diff --git a/composer.json b/composer.json
index c8f03f89..7f9de286 100644
--- a/composer.json
+++ b/composer.json
@@ -11,9 +11,6 @@
     "php": ">=7.2",
     "ext-grpc": "*",
     "ext-json": "*",
-    "ext-sysvmsg": "*",
-    "ext-sysvsem": "*",
-    "ext-sysvshm": "*",
     "laravel/framework": "~5.5|~6|~7|~8",
     "google/cloud-spanner": "^1.34",
     "grpc/grpc": "^1.36",
@@ -42,6 +39,11 @@
         "Colopl\\Spanner\\SpannerServiceProvider"
       ]
     }
+  },
+  "suggest": {
+    "ext-sysvmsg": "Can use SemaphoreLock for session handling. Will use FileLock if not present.",
+    "ext-sysvsem": "Can use SemaphoreLock for session handling. Will use FileLock if not present.",
+    "ext-sysvshm": "Can use SemaphoreLock for session handling. Will use FileLock if not present."
   }
 }