diff --git a/sim/mcuboot-sys/Cargo.toml b/sim/mcuboot-sys/Cargo.toml
index 19114f9..ac203f1 100644
--- a/sim/mcuboot-sys/Cargo.toml
+++ b/sim/mcuboot-sys/Cargo.toml
@@ -44,6 +44,9 @@
 # Encrypt image in the secondary slot using ECIES-P256
 enc-ec256 = []
 
+# Encrypt image in the secondary slot using ECIES-P256 using Mbed TLS
+enc-ec256-mbedtls = []
+
 # Encrypt image in the secondary slot using ECIES-X25519
 enc-x25519 = []
 
diff --git a/sim/mcuboot-sys/build.rs b/sim/mcuboot-sys/build.rs
index 74b19f0..df8c67e 100644
--- a/sim/mcuboot-sys/build.rs
+++ b/sim/mcuboot-sys/build.rs
@@ -21,6 +21,7 @@
     let enc_rsa = env::var("CARGO_FEATURE_ENC_RSA").is_ok();
     let enc_kw = env::var("CARGO_FEATURE_ENC_KW").is_ok();
     let enc_ec256 = env::var("CARGO_FEATURE_ENC_EC256").is_ok();
+    let enc_ec256_mbedtls = env::var("CARGO_FEATURE_ENC_EC256_MBEDTLS").is_ok();
     let enc_x25519 = env::var("CARGO_FEATURE_ENC_X25519").is_ok();
     let bootstrap = env::var("CARGO_FEATURE_BOOTSTRAP").is_ok();
     let multiimage = env::var("CARGO_FEATURE_MULTIIMAGE").is_ok();
@@ -230,6 +231,26 @@
         conf.file("../../ext/tinycrypt/lib/source/ctr_mode.c");
         conf.file("../../ext/tinycrypt/lib/source/hmac.c");
         conf.file("../../ext/tinycrypt/lib/source/ecc_dh.c");
+    } else if enc_ec256_mbedtls {
+        conf.define("MCUBOOT_ENCRYPT_EC256", None);
+        conf.define("MCUBOOT_ENC_IMAGES", None);
+        conf.define("MCUBOOT_USE_MBED_TLS", None);
+        conf.define("MCUBOOT_SWAP_SAVE_ENCTLV", None);
+
+        conf.include("../../ext/mbedtls/crypto/include");
+
+        conf.file("../../boot/bootutil/src/encrypted.c");
+        conf.file("../../ext/mbedtls/crypto/library/sha256.c");
+        conf.file("../../ext/mbedtls/crypto/library/asn1parse.c");
+        conf.file("../../ext/mbedtls/crypto/library/bignum.c");
+        conf.file("../../ext/mbedtls/crypto/library/ecdh.c");
+        conf.file("../../ext/mbedtls/crypto/library/md.c");
+        conf.file("../../ext/mbedtls/crypto/library/aes.c");
+        conf.file("../../ext/mbedtls/crypto/library/ecp.c");
+        conf.file("../../ext/mbedtls/crypto/library/ecp_curves.c");
+        conf.file("../../ext/mbedtls/crypto/library/platform.c");
+        conf.file("../../ext/mbedtls/crypto/library/platform_util.c");
+        conf.file("csupport/keys.c");
     }
 
     if enc_x25519 {
@@ -263,8 +284,8 @@
         conf.define("MBEDTLS_CONFIG_FILE", Some("<config-rsa-kw.h>"));
     } else if sig_rsa || sig_rsa3072 || enc_rsa {
         conf.define("MBEDTLS_CONFIG_FILE", Some("<config-rsa.h>"));
-    } else if sig_ecdsa_mbedtls {
-        conf.define("MBEDTLS_CONFIG_FILE", Some("<config-ecdsa.h>"));
+    } else if sig_ecdsa_mbedtls || enc_ec256_mbedtls {
+        conf.define("MBEDTLS_CONFIG_FILE", Some("<config-ec.h>"));
     } else if (sig_ecdsa || enc_ec256) && !enc_kw {
         conf.define("MBEDTLS_CONFIG_FILE", Some("<config-asn1.h>"));
     } else if sig_ed25519 || enc_x25519 {
diff --git a/sim/mcuboot-sys/csupport/run.c b/sim/mcuboot-sys/csupport/run.c
index 0133262..2bea140 100644
--- a/sim/mcuboot-sys/csupport/run.c
+++ b/sim/mcuboot-sys/csupport/run.c
@@ -231,7 +231,8 @@
     struct boot_loader_state *state;
 
 #if defined(MCUBOOT_SIGN_RSA) || \
-    (defined(MCUBOOT_SIGN_EC256) && defined(MCUBOOT_USE_MBED_TLS))
+    (defined(MCUBOOT_SIGN_EC256) && defined(MCUBOOT_USE_MBED_TLS)) ||\
+    (defined(MCUBOOT_ENCRYPT_EC256) && defined(MCUBOOT_USE_MBED_TLS))
     mbedtls_platform_set_calloc_free(calloc, free);
 #endif