diff --git a/include/mbedtls/oid.h b/include/mbedtls/oid.h
index 6fbd018..65e626e 100644
--- a/include/mbedtls/oid.h
+++ b/include/mbedtls/oid.h
@@ -43,13 +43,31 @@
 #include "md.h"
 #endif
 
-#if defined(MBEDTLS_X509_USE_C) || defined(MBEDTLS_X509_CREATE_C)
-#include "x509.h"
-#endif
-
 #define MBEDTLS_ERR_OID_NOT_FOUND                         -0x002E  /**< OID is not found. */
 #define MBEDTLS_ERR_OID_BUF_TOO_SMALL                     -0x000B  /**< output buffer is too small */
 
+/* This is for the benefit of X.509, but defined here in order to avoid
+ * having a "backwards" include of x.509.h here */
+/*
+ * X.509 extension types (internal, arbitrary values for bitsets)
+ */
+#define MBEDTLS_OID_X509_EXT_AUTHORITY_KEY_IDENTIFIER    (1 << 0)
+#define MBEDTLS_OID_X509_EXT_SUBJECT_KEY_IDENTIFIER      (1 << 1)
+#define MBEDTLS_OID_X509_EXT_KEY_USAGE                   (1 << 2)
+#define MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES        (1 << 3)
+#define MBEDTLS_OID_X509_EXT_POLICY_MAPPINGS             (1 << 4)
+#define MBEDTLS_OID_X509_EXT_SUBJECT_ALT_NAME            (1 << 5)
+#define MBEDTLS_OID_X509_EXT_ISSUER_ALT_NAME             (1 << 6)
+#define MBEDTLS_OID_X509_EXT_SUBJECT_DIRECTORY_ATTRS     (1 << 7)
+#define MBEDTLS_OID_X509_EXT_BASIC_CONSTRAINTS           (1 << 8)
+#define MBEDTLS_OID_X509_EXT_NAME_CONSTRAINTS            (1 << 9)
+#define MBEDTLS_OID_X509_EXT_POLICY_CONSTRAINTS          (1 << 10)
+#define MBEDTLS_OID_X509_EXT_EXTENDED_KEY_USAGE          (1 << 11)
+#define MBEDTLS_OID_X509_EXT_CRL_DISTRIBUTION_POINTS     (1 << 12)
+#define MBEDTLS_OID_X509_EXT_INIHIBIT_ANYPOLICY          (1 << 13)
+#define MBEDTLS_OID_X509_EXT_FRESHEST_CRL                (1 << 14)
+#define MBEDTLS_OID_X509_EXT_NS_CERT_TYPE                (1 << 16)
+
 /*
  * Top level OID tuples
  */
@@ -424,7 +442,6 @@
  */
 int mbedtls_oid_get_numeric_string( char *buf, size_t size, const mbedtls_asn1_buf *oid );
 
-#if defined(MBEDTLS_X509_USE_C) || defined(MBEDTLS_X509_CREATE_C)
 /**
  * \brief          Translate an X.509 extension OID into local values
  *
@@ -434,7 +451,6 @@
  * \return         0 if successful, or MBEDTLS_ERR_OID_NOT_FOUND
  */
 int mbedtls_oid_get_x509_ext_type( const mbedtls_asn1_buf *oid, int *ext_type );
-#endif
 
 /**
  * \brief          Translate an X.509 attribute type OID into the short name
diff --git a/include/mbedtls/x509.h b/include/mbedtls/x509.h
index 63aae32..b63e864 100644
--- a/include/mbedtls/x509.h
+++ b/include/mbedtls/x509.h
@@ -142,24 +142,26 @@
  *
  * Comments refer to the status for using certificates. Status can be
  * different for writing certificates or reading CRLs or CSRs.
+ *
+ * Those are defined in oid.h as oid.c needs them in a data structure. Since
+ * these were previously defined here, let's have aliases for compatibility.
  */
-#define MBEDTLS_X509_EXT_AUTHORITY_KEY_IDENTIFIER    (1 << 0)
-#define MBEDTLS_X509_EXT_SUBJECT_KEY_IDENTIFIER      (1 << 1)
-#define MBEDTLS_X509_EXT_KEY_USAGE                   (1 << 2)
-#define MBEDTLS_X509_EXT_CERTIFICATE_POLICIES        (1 << 3)
-#define MBEDTLS_X509_EXT_POLICY_MAPPINGS             (1 << 4)
-#define MBEDTLS_X509_EXT_SUBJECT_ALT_NAME            (1 << 5)    /* Supported (DNS) */
-#define MBEDTLS_X509_EXT_ISSUER_ALT_NAME             (1 << 6)
-#define MBEDTLS_X509_EXT_SUBJECT_DIRECTORY_ATTRS     (1 << 7)
-#define MBEDTLS_X509_EXT_BASIC_CONSTRAINTS           (1 << 8)    /* Supported */
-#define MBEDTLS_X509_EXT_NAME_CONSTRAINTS            (1 << 9)
-#define MBEDTLS_X509_EXT_POLICY_CONSTRAINTS          (1 << 10)
-#define MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE          (1 << 11)
-#define MBEDTLS_X509_EXT_CRL_DISTRIBUTION_POINTS     (1 << 12)
-#define MBEDTLS_X509_EXT_INIHIBIT_ANYPOLICY          (1 << 13)
-#define MBEDTLS_X509_EXT_FRESHEST_CRL                (1 << 14)
-
-#define MBEDTLS_X509_EXT_NS_CERT_TYPE                (1 << 16)
+#define MBEDTLS_X509_EXT_AUTHORITY_KEY_IDENTIFIER MBEDTLS_OID_X509_EXT_AUTHORITY_KEY_IDENTIFIER
+#define MBEDTLS_X509_EXT_SUBJECT_KEY_IDENTIFIER   MBEDTLS_OID_X509_EXT_SUBJECT_KEY_IDENTIFIER
+#define MBEDTLS_X509_EXT_KEY_USAGE                MBEDTLS_OID_X509_EXT_KEY_USAGE
+#define MBEDTLS_X509_EXT_CERTIFICATE_POLICIES     MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES
+#define MBEDTLS_X509_EXT_POLICY_MAPPINGS          MBEDTLS_OID_X509_EXT_POLICY_MAPPINGS
+#define MBEDTLS_X509_EXT_SUBJECT_ALT_NAME         MBEDTLS_OID_X509_EXT_SUBJECT_ALT_NAME         /* Supported (DNS) */
+#define MBEDTLS_X509_EXT_ISSUER_ALT_NAME          MBEDTLS_OID_X509_EXT_ISSUER_ALT_NAME
+#define MBEDTLS_X509_EXT_SUBJECT_DIRECTORY_ATTRS  MBEDTLS_OID_X509_EXT_SUBJECT_DIRECTORY_ATTRS
+#define MBEDTLS_X509_EXT_BASIC_CONSTRAINTS        MBEDTLS_OID_X509_EXT_BASIC_CONSTRAINTS        /* Supported */
+#define MBEDTLS_X509_EXT_NAME_CONSTRAINTS         MBEDTLS_OID_X509_EXT_NAME_CONSTRAINTS
+#define MBEDTLS_X509_EXT_POLICY_CONSTRAINTS       MBEDTLS_OID_X509_EXT_POLICY_CONSTRAINTS
+#define MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE       MBEDTLS_OID_X509_EXT_EXTENDED_KEY_USAGE
+#define MBEDTLS_X509_EXT_CRL_DISTRIBUTION_POINTS  MBEDTLS_OID_X509_EXT_CRL_DISTRIBUTION_POINTS
+#define MBEDTLS_X509_EXT_INIHIBIT_ANYPOLICY       MBEDTLS_OID_X509_EXT_INIHIBIT_ANYPOLICY
+#define MBEDTLS_X509_EXT_FRESHEST_CRL             MBEDTLS_OID_X509_EXT_FRESHEST_CRL
+#define MBEDTLS_X509_EXT_NS_CERT_TYPE             MBEDTLS_OID_X509_EXT_NS_CERT_TYPE
 
 /*
  * Storage format identifiers
diff --git a/library/oid.c b/library/oid.c
index edea950..294bbd6 100644
--- a/library/oid.c
+++ b/library/oid.c
@@ -41,10 +41,6 @@
 #define mbedtls_snprintf snprintf
 #endif
 
-#if defined(MBEDTLS_X509_USE_C) || defined(MBEDTLS_X509_CREATE_C)
-#include "mbedtls/x509.h"
-#endif
-
 /*
  * Macro to automatically add the size of #define'd OIDs
  */
@@ -152,7 +148,6 @@
     return( MBEDTLS_ERR_OID_NOT_FOUND );                                   \
 }
 
-#if defined(MBEDTLS_X509_USE_C) || defined(MBEDTLS_X509_CREATE_C)
 /*
  * For X520 attribute types
  */
@@ -260,23 +255,23 @@
 {
     {
         { ADD_LEN( MBEDTLS_OID_BASIC_CONSTRAINTS ),    "id-ce-basicConstraints",   "Basic Constraints" },
-        MBEDTLS_X509_EXT_BASIC_CONSTRAINTS,
+        MBEDTLS_OID_X509_EXT_BASIC_CONSTRAINTS,
     },
     {
         { ADD_LEN( MBEDTLS_OID_KEY_USAGE ),            "id-ce-keyUsage",           "Key Usage" },
-        MBEDTLS_X509_EXT_KEY_USAGE,
+        MBEDTLS_OID_X509_EXT_KEY_USAGE,
     },
     {
         { ADD_LEN( MBEDTLS_OID_EXTENDED_KEY_USAGE ),   "id-ce-extKeyUsage",        "Extended Key Usage" },
-        MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE,
+        MBEDTLS_OID_X509_EXT_EXTENDED_KEY_USAGE,
     },
     {
         { ADD_LEN( MBEDTLS_OID_SUBJECT_ALT_NAME ),     "id-ce-subjectAltName",     "Subject Alt Name" },
-        MBEDTLS_X509_EXT_SUBJECT_ALT_NAME,
+        MBEDTLS_OID_X509_EXT_SUBJECT_ALT_NAME,
     },
     {
         { ADD_LEN( MBEDTLS_OID_NS_CERT_TYPE ),         "id-netscape-certtype",     "Netscape Certificate Type" },
-        MBEDTLS_X509_EXT_NS_CERT_TYPE,
+        MBEDTLS_OID_X509_EXT_NS_CERT_TYPE,
     },
     {
         { NULL, 0, NULL, NULL },
@@ -300,7 +295,6 @@
 
 FN_OID_TYPED_FROM_ASN1(mbedtls_oid_descriptor_t, ext_key_usage, oid_ext_key_usage)
 FN_OID_GET_ATTR1(mbedtls_oid_get_extended_key_usage, mbedtls_oid_descriptor_t, ext_key_usage, const char *, description)
-#endif /* MBEDTLS_X509_USE_C || MBEDTLS_X509_CREATE_C */
 
 #if defined(MBEDTLS_MD_C)
 /*