diff --git a/interface/CMakeLists.txt b/interface/CMakeLists.txt
index 9a0c7e0..f3434e2 100644
--- a/interface/CMakeLists.txt
+++ b/interface/CMakeLists.txt
@@ -41,7 +41,7 @@
 target_compile_definitions(psa_interface
     INTERFACE
         $<$<BOOL:${CONFIG_TFM_ENABLE_CTX_MGMT}>:CONFIG_TFM_ENABLE_CTX_MGMT>
-        $<$<BOOL:${TFM_ISOLATION_LEVEL}>:TFM_LVL=${TFM_ISOLATION_LEVEL}>
+        $<$<BOOL:${TFM_ISOLATION_LEVEL}>:TFM_ISOLATION_LEVEL=${TFM_ISOLATION_LEVEL}>
         $<$<BOOL:${CONFIG_TFM_USE_TRUSTZONE}>:CONFIG_TFM_USE_TRUSTZONE>
         $<$<BOOL:${TFM_MULTI_CORE_TOPOLOGY}>:TFM_MULTI_CORE_TOPOLOGY>
         $<$<BOOL:${CONFIG_TFM_PARTITION_META}>:CONFIG_TFM_PARTITION_META>