diff --git a/internal/services/postgres/postgresql_flexible_server_resource.go b/internal/services/postgres/postgresql_flexible_server_resource.go
index fc345581f7ec..28f6be42abcd 100644
--- a/internal/services/postgres/postgresql_flexible_server_resource.go
+++ b/internal/services/postgres/postgresql_flexible_server_resource.go
@@ -129,7 +129,7 @@ func resourcePostgresqlFlexibleServer() *pluginsdk.Resource {
 				Type:         pluginsdk.TypeInt,
 				Optional:     true,
 				Computed:     true,
-				ValidateFunc: validation.IntInSlice([]int{32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33553408}),
+				ValidateFunc: validation.IntInSlice([]int{32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4193280, 4194304, 8388608, 16777216, 33553408}),
 			},
 
 			"version": {
diff --git a/website/docs/r/postgresql_flexible_server.html.markdown b/website/docs/r/postgresql_flexible_server.html.markdown
index 9995637376b7..be26995aaa06 100644
--- a/website/docs/r/postgresql_flexible_server.html.markdown
+++ b/website/docs/r/postgresql_flexible_server.html.markdown
@@ -132,7 +132,7 @@ The following arguments are supported:
 
 * `auto_grow_enabled` - (Optional) Is the storage auto grow for PostgreSQL Flexible Server enabled? Defaults to `false`.
 
-* `storage_mb` - (Optional) The max storage allowed for the PostgreSQL Flexible Server. Possible values are `32768`, `65536`, `131072`, `262144`, `524288`, `1048576`, `2097152`, `4194304`, `8388608`, `16777216` and `33553408`.
+* `storage_mb` - (Optional) The max storage allowed for the PostgreSQL Flexible Server. Possible values are `32768`, `65536`, `131072`, `262144`, `524288`, `1048576`, `2097152`, `4193280`, `4194304`, `8388608`, `16777216` and `33553408`.
 
 * `tags` - (Optional) A mapping of tags which should be assigned to the PostgreSQL Flexible Server.