diff --git a/dht/murmur3_partitioner.cc b/dht/murmur3_partitioner.cc
index 20faaa09dc..ca4a0a7803 100644
--- a/dht/murmur3_partitioner.cc
+++ b/dht/murmur3_partitioner.cc
@@ -130,7 +130,7 @@ murmur3_partitioner::bias(uint64_t n) const {
 }
 
 sstring murmur3_partitioner::to_sstring(const token& t) const {
-    return ::to_sstring<sstring>(long_token(t));
+    return seastar::to_sstring<sstring>(long_token(t));
 }
 
 dht::token murmur3_partitioner::from_sstring(const sstring& t) const {
diff --git a/seastarx.hh b/seastarx.hh
index be002be49a..8c424816bd 100644
--- a/seastarx.hh
+++ b/seastarx.hh
@@ -28,6 +28,9 @@ namespace seastar {
 template <typename T>
 class shared_ptr;
 
+template <typename T>
+shared_ptr<T> make_shared(T&&);
+
 template <typename T, typename... A>
 shared_ptr<T> make_shared(A&&... a);
 
diff --git a/stdx.hh b/stdx.hh
index a579a7977f..d2d78e4a60 100644
--- a/stdx.hh
+++ b/stdx.hh
@@ -23,4 +23,5 @@
 #pragma once
 
 namespace std { namespace experimental {} }
-inline namespace seastar { namespace stdx = std::experimental; }
+namespace seastar { namespace stdx = std::experimental; }
+using namespace seastar;
diff --git a/tests/perf/perf_fast_forward.cc b/tests/perf/perf_fast_forward.cc
index c0941b4dcc..b49c9113ff 100644
--- a/tests/perf/perf_fast_forward.cc
+++ b/tests/perf/perf_fast_forward.cc
@@ -556,7 +556,7 @@ int main(int argc, char** argv) {
 
                     std::cout << "Config: rows: " << cfg.n_rows << ", value size: " << cfg.value_size << "\n";
 
-                    ::sleep(1s).get(); // wait for system table flushes to quiesce
+                    sleep(1s).get(); // wait for system table flushes to quiesce
 
                     bool cancel = false;
                     engine().at_exit([&] {