diff --git a/cyassl/ctaocrypt/settings.h b/cyassl/ctaocrypt/settings.h
index 517c14d46..d01deba82 100644
--- a/cyassl/ctaocrypt/settings.h
+++ b/cyassl/ctaocrypt/settings.h
@@ -165,6 +165,7 @@
     #define USE_FAST_MATH
     #define TFM_TIMING_RESISTANT
     #define TFM_ECC256
+    #define TFM_ARM
     #define ECC_SHAMIR
     #define FP_ECC
     #define FP_ENTRIES 2