diff --git a/lib/ruby2ruby.rb b/lib/ruby2ruby.rb
index a3fb5af..d68d828 100755
--- a/lib/ruby2ruby.rb
+++ b/lib/ruby2ruby.rb
@@ -609,7 +609,11 @@ def process_in exp # :nodoc:
     _, lhs, *rhs = exp
 
     cond = process lhs
-    body = rhs.compact.map { |sexp| indent process sexp }
+    body = rhs.compact.map { |sexp|
+      in_context :in_body do
+        indent process sexp
+      end
+    }
 
     body << indent("# do nothing") if body.empty?
     body = body.join "\n"
diff --git a/test/test_ruby2ruby.rb b/test/test_ruby2ruby.rb
index 2def801..b57a14d 100644
--- a/test/test_ruby2ruby.rb
+++ b/test/test_ruby2ruby.rb
@@ -1002,6 +1002,16 @@ def test_case_in__hash_pat_14
     assert_case_in "Object[b: 1]", s(:hash_pat, s(:const, :Object), s(:lit, :b), s(:lit, 1))
   end
 
+  def test_case_in_body_does_not_pin_variables
+    inn = s(:case, s(:call, nil, :x),
+            s(:in,
+              s(:array_pat, nil, s(:lasgn, :a), s(:lasgn, :b)),
+              s(:lvar, :a)),
+            nil)
+    out = "case x\nin [a, b] then\n  a\nend"
+    assert_parse inn, out
+  end
+
   def test_interpolation_and_escapes
     # log_entry = "  \e[#{message_color}m#{message}\e[0m   "
     inn = s(:lasgn, :log_entry,