diff --git a/src/drivers/device/vdev.cpp b/src/drivers/device/vdev.cpp
index 330447086c..9e2c39062f 100644
--- a/src/drivers/device/vdev.cpp
+++ b/src/drivers/device/vdev.cpp
@@ -548,6 +548,7 @@ void VDev::showDevices()
 
 	pthread_mutex_unlock(&devmutex);
 
+#ifndef __PX4_UNIT_TESTS
 	PX4_INFO("DF Devices:");
 	const char *dev_path;
 	unsigned int index = 0;
@@ -561,6 +562,7 @@ void VDev::showDevices()
 			PX4_INFO("   %s", dev_path);
 		}
 	} while (i == 0);
+#endif
 }
 
 void VDev::showTopics()
diff --git a/unittests/CMakeLists.txt b/unittests/CMakeLists.txt
index 684ac9a6de..c7e62a3535 100644
--- a/unittests/CMakeLists.txt
+++ b/unittests/CMakeLists.txt
@@ -26,9 +26,9 @@ include(CheckCXXCompilerFlag)
 CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
 CHECK_CXX_COMPILER_FLAG("-std=c++0x" COMPILER_SUPPORTS_CXX0X)
 if(COMPILER_SUPPORTS_CXX11)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -fno-exceptions -fno-rtti -fno-threadsafe-statics -D__CUSTOM_FILE_IO__ -g -Wall")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -fno-exceptions -fno-rtti -fno-threadsafe-statics -D__CUSTOM_FILE_IO__ -D__PX4_UNIT_TESTS -g -Wall")
 elseif(COMPILER_SUPPORTS_CXX0X)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x -fno-exceptions -fno-rtti -fno-threadsafe-statics -D__CUSTOM_FILE_IO__ -g -Wall")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x -fno-exceptions -fno-rtti -fno-threadsafe-statics -D__CUSTOM_FILE_IO__ -D__PX4_UNIT_TESTS -g -Wall")
 else()
   message(STATUS "The compiler ${CMAKE_CXX_COMPILER} has no C++11 support. Please use a different C++ compiler.")
 endif()