diff --git a/library/x509_csr.c b/library/x509_csr.c
index 9bdfe88..b3c8f29 100644
--- a/library/x509_csr.c
+++ b/library/x509_csr.c
@@ -169,14 +169,14 @@
         return( ret );
     }
 
-    csr->version++;
-
-    if( csr->version != 1 )
+    if( csr->version != 0 )
     {
         x509_csr_free( csr );
         return( POLARSSL_ERR_X509_UNKNOWN_VERSION );
     }
 
+    csr->version++;
+
     /*
      *  subject               Name
      */