diff --git a/boot/boot_serial/test/syscfg.yml b/boot/boot_serial/test/syscfg.yml
index ff841d626c..07baa99795 100644
--- a/boot/boot_serial/test/syscfg.yml
+++ b/boot/boot_serial/test/syscfg.yml
@@ -21,3 +21,6 @@
 syscfg.vals:
     # This is here to work around the $notnull syscfg restriction.
     BOOT_SERIAL_DETECT_PIN: 0
+
+syscfg.vals.BOOTUTIL_USE_MBED_TLS:
+    MBEDTLS_CIPHER_MODE_CTR: 1
diff --git a/boot/bootutil/pkg.yml b/boot/bootutil/pkg.yml
index 4a7fabc1ca..c5d713b691 100644
--- a/boot/bootutil/pkg.yml
+++ b/boot/bootutil/pkg.yml
@@ -31,9 +31,6 @@ pkg.apis:
 pkg.cflags:
     - "-DMCUBOOT_MYNEWT=1"
 
-pkg.cflags.BOOTUTIL_USE_MBED_TLS:
-    - '-DMBEDTLS_USER_CONFIG_FILE="mbedtls/config_mynewt.h"'
-
 pkg.deps:
     - "@mcuboot/boot/mynewt/mcuboot_config"
     - "@apache-mynewt-core/hw/hal"
diff --git a/ci/mynewt_keys/enc_rsa/pkg.yml b/ci/mynewt_keys/enc_rsa/pkg.yml
index 61918f1b45..619832c54c 100644
--- a/ci/mynewt_keys/enc_rsa/pkg.yml
+++ b/ci/mynewt_keys/enc_rsa/pkg.yml
@@ -20,6 +20,3 @@
 pkg.name: keys/enc_rsa
 pkg.author: "Apache Mynewt <dev@mynewt.apache.org>"
 pkg.homepage: "http://mynewt.apache.org/"
-
-pkg.cflags:
-    - '-DMBEDTLS_USER_CONFIG_FILE="mbedtls/config_mynewt.h"'