diff --git a/parser/prism/Translator.cc b/parser/prism/Translator.cc
index 77338ea11a8..c427116f420 100644
--- a/parser/prism/Translator.cc
+++ b/parser/prism/Translator.cc
@@ -1044,7 +1044,19 @@ unique_ptr<parser::Node> Translator::translate(pm_node_t *node) {
             if (paramsNode->rest != nullptr)
                 params.emplace_back(translate(paramsNode->rest));
 
-            translateMultiInto(params, posts);
+            // Note: This is actually a divergence from the legacy Sorbet parser behavior, which doesn't handle `**nil`
+            //   as a post argument. In this case, the legacy parser would just replace the entire tree with `Nil`.
+            for (auto &post : posts) {
+                switch (PM_NODE_TYPE(post)) {
+                    case PM_NO_KEYWORDS_PARAMETER_NODE: { // `**nil`
+                        params.emplace_back(translateSimpleKeyword<parser::Kwnilarg>(post));
+                        break;
+                    }
+                    default:
+                        params.emplace_back(translate(post));
+                }
+            }
+
             translateMultiInto(params, keywords);
 
             if (auto prismKwRestNode = paramsNode->keyword_rest; prismKwRestNode != nullptr) {