diff --git a/prism_compile.c b/prism_compile.c
index da093e1861..4d1d0d851f 100644
--- a/prism_compile.c
+++ b/prism_compile.c
@@ -2560,6 +2560,7 @@ pm_compile_defined_expr0(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *co
       case PM_NEXT_NODE:
       case PM_OR_NODE:
       case PM_RANGE_NODE:
+      case PM_RATIONAL_NODE:
       case PM_REDO_NODE:
       case PM_REGULAR_EXPRESSION_NODE:
       case PM_RETRY_NODE:
diff --git a/test/ruby/test_compile_prism.rb b/test/ruby/test_compile_prism.rb
index a635683fc3..63e1a31199 100644
--- a/test/ruby/test_compile_prism.rb
+++ b/test/ruby/test_compile_prism.rb
@@ -258,6 +258,7 @@ module Prism
       assert_prism_eval("defined?(/(?<foo>bar)/ =~ 'barbar')")
       assert_prism_eval("defined?(1 => 1)")
       assert_prism_eval("defined?(module M; end)")
+      assert_prism_eval("defined?(1.2r)")
     end
 
     def test_GlobalVariableReadNode