diff --git a/test/unit_test/static/custom_rep_test_min_expl.cpp b/test/unit_test/static/custom_rep_test_min_expl.cpp
index 8529f459..30f80ec4 100644
--- a/test/unit_test/static/custom_rep_test_min_expl.cpp
+++ b/test/unit_test/static/custom_rep_test_min_expl.cpp
@@ -21,6 +21,7 @@
 // SOFTWARE.
 
 #include "units/physical/si/base/length.h"
+#include <ostream>
 
 namespace {
 
diff --git a/test/unit_test/static/unit_constants.cpp b/test/unit_test/static/unit_constants.cpp
index 84e9dfbd..35d6a17c 100644
--- a/test/unit_test/static/unit_constants.cpp
+++ b/test/unit_test/static/unit_constants.cpp
@@ -36,9 +36,10 @@
 #pragma warning( disable : 4459 ) // Disable shadowing warning.
 #endif
 
+using namespace units;
 using namespace units::physical;
-using namespace si;
-using namespace unit_constants;
+using namespace units::physical::si;
+using namespace units::physical::si::unit_constants;
 
 static_assert(2 * m == 2_q_m);
 static_assert(2 * s == 2_q_s);