diff --git a/targets/common/CMakeLists.txt b/targets/common/CMakeLists.txt
index fa9b953..f3382f3 100644
--- a/targets/common/CMakeLists.txt
+++ b/targets/common/CMakeLists.txt
@@ -52,9 +52,7 @@
 # Startup
 add_library(ethosu_target_startup INTERFACE)
 target_link_libraries(ethosu_target_startup INTERFACE ethosu_target_link)
-
-target_link_libraries(ethosu_target_startup INTERFACE $<TARGET_OBJECTS:cmsis_startup>)
-add_dependencies(ethosu_target_startup $<TARGET_OBJECTS:cmsis_startup>)
+target_link_libraries(ethosu_target_startup INTERFACE cmsis_system)
 
 # Init
 add_library(ethosu_target_init INTERFACE)
diff --git a/targets/corstone-300/CMakeLists.txt b/targets/corstone-300/CMakeLists.txt
index d162537..03226c7 100644
--- a/targets/corstone-300/CMakeLists.txt
+++ b/targets/corstone-300/CMakeLists.txt
@@ -50,6 +50,9 @@
 # Corstone-300
 #############################################################################
 
+# Enable trustzone support in core_software
+set(TRUSTZONE_BUILD ON)
+
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/../common target)
 
 # Linker script