diff --git a/ext/mbedtls b/ext/mbedtls
index 8df2f8e7b..daca7a397 160000
--- a/ext/mbedtls
+++ b/ext/mbedtls
@@ -1 +1 @@
-Subproject commit 8df2f8e7b9c7bb9390ac74bb7bace27edca81a2b
+Subproject commit daca7a3979c22da155ec9dce49ab1abf3b65d3a9
diff --git a/sim/mcuboot-sys/build.rs b/sim/mcuboot-sys/build.rs
index 4221292f5..90077985c 100644
--- a/sim/mcuboot-sys/build.rs
+++ b/sim/mcuboot-sys/build.rs
@@ -169,6 +169,8 @@ fn main() {
 
         conf.file("../../ext/mbedtls/library/rsa.c");
         conf.file("../../ext/mbedtls/library/bignum.c");
+        conf.file("../../ext/mbedtls/library/bignum_core.c");
+        conf.file("../../ext/mbedtls/library/constant_time.c");
         conf.file("../../ext/mbedtls/library/platform.c");
         conf.file("../../ext/mbedtls/library/platform_util.c");
         conf.file("../../ext/mbedtls/library/asn1parse.c");