diff --git a/test/ruby/test_weakmap.rb b/test/ruby/test_weakmap.rb
index c72e7310db1017..7fc956dfae4747 100644
--- a/test/ruby/test_weakmap.rb
+++ b/test/ruby/test_weakmap.rb
@@ -178,6 +178,8 @@ def test_no_memory_leak
   end
 
   def test_compaction_bug_19529
+    omit "compaction is not supported on this platform" unless GC.respond_to?(:compact)
+
     obj = Object.new
     100.times do |i|
       GC.compact