diff --git a/include/simstr/sstring.h b/include/simstr/sstring.h
index df5b9c4..9b056fc 100644
--- a/include/simstr/sstring.h
+++ b/include/simstr/sstring.h
@@ -5631,17 +5631,17 @@ public:
         return try_emplace(std::forward<Key>(key)).first->second;
     }
 
-    auto at(const StoreType<K>& key) {
+    decltype(auto) at(const StoreType<K>& key) {
         return hash_t::at(key);
     }
-    auto at(const StoreType<K>& key) const {
+    decltype(auto) at(const StoreType<K>& key) const {
         return hash_t::at(key);
     }
 
-    auto at(simple_str<K> key) {
+    decltype(auto) at(simple_str<K> key) {
         return hash_t::at(toStoreType(key));
     }
-    auto at(simple_str<K> key) const {
+    decltype(auto) at(simple_str<K> key) const {
         return hash_t::at(toStoreType(key));
     }
 
diff --git a/tests/test_str.cpp b/tests/test_str.cpp
index a2d60fb..1b4fa0b 100644
--- a/tests/test_str.cpp
+++ b/tests/test_str.cpp
@@ -1751,4 +1751,13 @@ TEST(SimStr, InitFromLValueStdStrings) {
     EXPECT_EQ(ssa(get_string_cref()), "str");
 }
 
+TEST(SimStr, HashStrMapAt) {
+    hashStrMapA<int> test = {
+        {"Test"_h, 1}
+    };
+    EXPECT_EQ(test.find("Test")->second, 1);
+    test.at("Test") = 2;
+    EXPECT_EQ(test.find("Test")->second, 2);
+}
+
 } // namespace simstr::tests