diff --git a/tests/identity-management-fixture.cpp b/tests/identity-management-fixture.cpp
index 254da23..86655c4 100644
--- a/tests/identity-management-fixture.cpp
+++ b/tests/identity-management-fixture.cpp
@@ -26,8 +26,7 @@
 
 #include <boost/filesystem.hpp>
 
-namespace ndncert {
-namespace tests {
+namespace ndncert::tests {
 
 using namespace ndn::security;
 
@@ -126,5 +125,4 @@
   return certificate;
 }
 
-} // namespace tests
-} // namespace ndncert
+} // namespace ndncert::tests