diff --git a/spec/std/socket/spec_helper.cr b/spec/std/socket/spec_helper.cr
index 276e2f4195f2..38aadaf802d9 100644
--- a/spec/std/socket/spec_helper.cr
+++ b/spec/std/socket/spec_helper.cr
@@ -2,7 +2,9 @@ require "spec"
 require "socket"
 
 module SocketSpecHelper
-  class_getter?(supports_ipv6 : Bool) do
+  class_getter?(supports_ipv6 : Bool) { detect_supports_ipv6? }
+
+  private def self.detect_supports_ipv6? : Bool
     TCPServer.open("::1", 0) { return true }
     false
   rescue Socket::Error
diff --git a/spec/support/time.cr b/spec/support/time.cr
index d550a83af2c3..2b4738b5d71e 100644
--- a/spec/support/time.cr
+++ b/spec/support/time.cr
@@ -72,7 +72,9 @@ end
     # Enable the `SeTimeZonePrivilege` privilege before changing the system time
     # zone. This is necessary because the privilege is by default granted but
     # disabled for any new process. This only needs to be done once per run.
-    class_getter? time_zone_privilege_enabled : Bool do
+    class_getter?(time_zone_privilege_enabled : Bool) { detect_time_zone_privilege_enabled? }
+
+    private def self.detect_time_zone_privilege_enabled? : Bool
       if LibC.LookupPrivilegeValueW(nil, SeTimeZonePrivilege, out time_zone_luid) == 0
         raise RuntimeError.from_winerror("LookupPrivilegeValueW")
       end