diff --git a/prism_compile.c b/prism_compile.c
index 2f0161fb47e51e..95544ccda16c54 100644
--- a/prism_compile.c
+++ b/prism_compile.c
@@ -1437,6 +1437,7 @@ pm_scope_node_init(const pm_node_t *node, pm_scope_node_t *scope, pm_scope_node_
         case PM_INTERPOLATED_REGULAR_EXPRESSION_NODE: {
             RUBY_ASSERT(node->flags & PM_REGULAR_EXPRESSION_FLAGS_ONCE);
             scope->body = (pm_node_t *)node;
+            scope->local_depth_offset += 1;
             break;
         }
         case PM_LAMBDA_NODE: {
diff --git a/test/ruby/test_compile_prism.rb b/test/ruby/test_compile_prism.rb
index e95baf5d5c0725..0409fc3e468ef1 100644
--- a/test/ruby/test_compile_prism.rb
+++ b/test/ruby/test_compile_prism.rb
@@ -601,6 +601,7 @@ def test_RegularExpressionNode
       assert_prism_eval('/pit/ne')
 
       assert_prism_eval('2.times.map { /#{1}/o }')
+      assert_prism_eval('2.times.map { foo = 1; /#{foo}/o }')
     end
 
     def test_StringNode