diff --git a/boot/zephyr/include/config-ed25519.h b/boot/zephyr/include/config-ed25519.h
index fb0750a..3efb7bd 100644
--- a/boot/zephyr/include/config-ed25519.h
+++ b/boot/zephyr/include/config-ed25519.h
@@ -52,6 +52,8 @@
 #define MBEDTLS_HAVE_ASM
 #endif
 
+#define MBEDTLS_CIPHER_MODE_CTR
+
 /* mbed TLS modules */
 #define MBEDTLS_ASN1_PARSE_C
 #define MBEDTLS_BIGNUM_C
diff --git a/boot/zephyr/include/config-kw.h b/boot/zephyr/include/config-kw.h
index 41e5baa..0ed94d1 100644
--- a/boot/zephyr/include/config-kw.h
+++ b/boot/zephyr/include/config-kw.h
@@ -54,6 +54,8 @@
 #define MBEDTLS_HAVE_ASM
 #endif
 
+#define MBEDTLS_CIPHER_MODE_CTR
+
 #define MBEDTLS_SHA256_C
 #define MBEDTLS_AES_C
 #define MBEDTLS_CIPHER_C
diff --git a/boot/zephyr/include/config-rsa-kw.h b/boot/zephyr/include/config-rsa-kw.h
index eb9143c..99c9957 100644
--- a/boot/zephyr/include/config-rsa-kw.h
+++ b/boot/zephyr/include/config-rsa-kw.h
@@ -55,6 +55,8 @@
 #define MBEDTLS_RSA_C
 #define MBEDTLS_PKCS1_V21
 
+#define MBEDTLS_CIPHER_MODE_CTR
+
 /* mbed TLS modules */
 #define MBEDTLS_ASN1_PARSE_C
 #define MBEDTLS_BIGNUM_C
diff --git a/boot/zephyr/include/config-rsa.h b/boot/zephyr/include/config-rsa.h
index 3e05692..265b290 100644
--- a/boot/zephyr/include/config-rsa.h
+++ b/boot/zephyr/include/config-rsa.h
@@ -55,6 +55,8 @@
 #define MBEDTLS_RSA_C
 #define MBEDTLS_PKCS1_V21
 
+#define MBEDTLS_CIPHER_MODE_CTR
+
 /* mbed TLS modules */
 #define MBEDTLS_ASN1_PARSE_C
 #define MBEDTLS_ASN1_WRITE_C