diff --git a/cpp_utils/test/unittest/return_code/ReturnCodeTest.cpp b/cpp_utils/test/unittest/return_code/ReturnCodeTest.cpp
index 3fde534e..a8d84aca 100644
--- a/cpp_utils/test/unittest/return_code/ReturnCodeTest.cpp
+++ b/cpp_utils/test/unittest/return_code/ReturnCodeTest.cpp
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include <algorithm>
+#include <thread>
 
 #include <cpp_utils/testing/gtest_aux.hpp>
 #include <gtest/gtest.h>
diff --git a/cpp_utils/test/unittest/thread_pool/slot_thread_pool_test.cpp b/cpp_utils/test/unittest/thread_pool/slot_thread_pool_test.cpp
index a0836413..4c241471 100644
--- a/cpp_utils/test/unittest/thread_pool/slot_thread_pool_test.cpp
+++ b/cpp_utils/test/unittest/thread_pool/slot_thread_pool_test.cpp
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <thread>
+
 #include <cpp_utils/testing/gtest_aux.hpp>
 #include <gtest/gtest.h>