diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index 464c4ad..e4ed36a 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -42,7 +42,7 @@
 #define MBEDTLS_CIPHER_MODE_WITH_PADDING
 #endif
 
-#if defined(MBEDTLS_ARC4_C)
+#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
 #define MBEDTLS_CIPHER_MODE_STREAM
 #endif
 
diff --git a/include/mbedtls/cipher_internal.h b/include/mbedtls/cipher_internal.h
index 88baa82..6c58bcc 100644
--- a/include/mbedtls/cipher_internal.h
+++ b/include/mbedtls/cipher_internal.h
@@ -33,10 +33,6 @@
 
 #include "cipher.h"
 
-#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
-#define MBEDTLS_CIPHER_MODE_STREAM
-#endif
-
 #ifdef __cplusplus
 extern "C" {
 #endif