diff --git a/include/polarssl/x509_crl.h b/include/polarssl/x509_crl.h
index 3016b87..9f597a8 100644
--- a/include/polarssl/x509_crl.h
+++ b/include/polarssl/x509_crl.h
@@ -75,7 +75,7 @@
     x509_buf raw;           /**< The raw certificate data (DER). */
     x509_buf tbs;           /**< The raw certificate body (DER). The part that is To Be Signed. */
 
-    int version;
+    int version;            /**< CRL version (1=v1, 2=v2) */
     x509_buf sig_oid1;
 
     x509_buf issuer_raw;    /**< The raw issuer data (DER). */
diff --git a/include/polarssl/x509_crt.h b/include/polarssl/x509_crt.h
index e90e357..4bf8e56 100644
--- a/include/polarssl/x509_crt.h
+++ b/include/polarssl/x509_crt.h
@@ -59,7 +59,7 @@
     x509_buf raw;               /**< The raw certificate data (DER). */
     x509_buf tbs;               /**< The raw certificate body (DER). The part that is To Be Signed. */
 
-    int version;                /**< The X.509 version. (0=v1, 1=v2, 2=v3) */
+    int version;                /**< The X.509 version. (1=v1, 2=v2, 3=v3) */
     x509_buf serial;            /**< Unique id for certificate issued by a specific CA. */
     x509_buf sig_oid1;          /**< Signature algorithm, e.g. sha1RSA */
 
diff --git a/include/polarssl/x509_csr.h b/include/polarssl/x509_csr.h
index bbe6bec..6591e38 100644
--- a/include/polarssl/x509_csr.h
+++ b/include/polarssl/x509_csr.h
@@ -56,7 +56,7 @@
     x509_buf raw;           /**< The raw CSR data (DER). */
     x509_buf cri;           /**< The raw CertificateRequestInfo body (DER). */
 
-    int version;
+    int version;            /**< CSR version (1=v1). */
 
     x509_buf  subject_raw;  /**< The raw subject data (DER). */
     x509_name subject;      /**< The parsed subject data (named information object). */