diff --git a/scripts/make/cortex_m_ethos_eval_makefile.inc b/scripts/make/cortex_m_ethos_eval_makefile.inc
index 27bb9d6..234534a 100644
--- a/scripts/make/cortex_m_ethos_eval_makefile.inc
+++ b/scripts/make/cortex_m_ethos_eval_makefile.inc
@@ -139,6 +139,7 @@
     -fomit-frame-pointer \
     -MD \
     -DCPU_CORTEX_$(CORE)=1 \
+    -DETHOSU_ARCH=${ETHOSU_ARCH} \
     $(TARGET_SPECIFIC_FLAGS)
 
   # Common + C/C++ flags