diff --git a/test/ruby/test_gc_compact.rb b/test/ruby/test_gc_compact.rb
index 4a8cff33f4..8dfa66a177 100644
--- a/test/ruby/test_gc_compact.rb
+++ b/test/ruby/test_gc_compact.rb
@@ -133,18 +133,20 @@ class TestGCCompact < Test::Unit::TestCase
     assert_equal hash, list_of_objects.hash
   end
 
-  def walk_ast ast
-    children = ast.children.grep(RubyVM::AbstractSyntaxTree::Node)
-    children.each do |child|
-      assert child.type
-      walk_ast child
-    end
-  end
-
   def test_ast_compacts
-    ast = RubyVM::AbstractSyntaxTree.parse_file __FILE__
-    assert GC.compact
-    walk_ast ast
+    assert_separately([], "#{<<~"begin;"}\n#{<<~"end;"}", timeout: 10, signal: :SEGV)
+    begin;
+      def walk_ast ast
+        children = ast.children.grep(RubyVM::AbstractSyntaxTree::Node)
+        children.each do |child|
+          assert child.type
+          walk_ast child
+        end
+      end
+      ast = RubyVM::AbstractSyntaxTree.parse_file #{__FILE__.dump}
+      assert GC.compact
+      walk_ast ast
+    end;
   end
 
   def test_compact_count