diff --git a/interface/include/config_impl.h.template b/interface/include/config_impl.h.template
index a635514..83ae49e 100644
--- a/interface/include/config_impl.h.template
+++ b/interface/include/config_impl.h.template
@@ -24,7 +24,11 @@
 
 #if CONFIG_TFM_SPM_BACKEND_IPC == 1
 /* Trustzone NS agent working stack size. */
+#if defined(TFM_FIH_PROFILE_ON) && TFM_LVL == 1
+#define {{"%-56s"|format("CONFIG_TFM_NS_AGENT_TZ_STACK_SIZE")}} 1256
+#else
 #define {{"%-56s"|format("CONFIG_TFM_NS_AGENT_TZ_STACK_SIZE")}} 1024
+#endif
 
 /* SPM re-uses Trustzone NS agent stack. */
 #define {{"%-56s"|format("CONFIG_TFM_SPM_THREAD_STACK_SIZE")}}     \