diff --git a/tf-psa-crypto/drivers/builtin/src/bignum_core.h b/tf-psa-crypto/drivers/builtin/src/bignum_core.h
index 3c6b105e43..da75546d51 100644
--- a/tf-psa-crypto/drivers/builtin/src/bignum_core.h
+++ b/tf-psa-crypto/drivers/builtin/src/bignum_core.h
@@ -70,9 +70,7 @@
 
 #include "common.h"
 
-#if defined(MBEDTLS_BIGNUM_C)
 #include "mbedtls/bignum.h"
-#endif
 
 #include "constant_time_internal.h"