diff --git a/include/miniocpp/signer.h b/include/miniocpp/signer.h
index b8c912b..670a93d 100644
--- a/include/miniocpp/signer.h
+++ b/include/miniocpp/signer.h
@@ -69,7 +69,7 @@ utils::Multimap SignV4STS(http::Method method, const std::string& uri,
                           const utils::UtcTime& date);
 utils::Multimap PresignV4(http::Method method, const std::string& host,
                           const std::string& uri, const std::string& region,
-                          utils::Multimap query_params,
+                          utils::Multimap& query_params,
                           const std::string& access_key,
                           const std::string& secret_key,
                           const utils::UtcTime& date, unsigned int expires);
diff --git a/src/signer.cc b/src/signer.cc
index c3ffb59..067f6b0 100644
--- a/src/signer.cc
+++ b/src/signer.cc
@@ -165,7 +165,7 @@ utils::Multimap SignV4STS(http::Method method, const std::string& uri,
 
 utils::Multimap PresignV4(http::Method method, const std::string& host,
                           const std::string& uri, const std::string& region,
-                          utils::Multimap query_params,
+                          utils::Multimap& query_params,
                           const std::string& access_key,
                           const std::string& secret_key,
                           const utils::UtcTime& date, unsigned int expires) {