diff --git a/library/pkparse.c b/library/pkparse.c
index f0a12f983..e21470b27 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -175,6 +175,10 @@ static int pk_get_ecparams( unsigned char **p, const unsigned char *end,
 {
     int ret;
 
+    if ( end - *p < 1 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                MBEDTLS_ERR_ASN1_OUT_OF_DATA );
+
     /* Tag may be either OID or SEQUENCE */
     params->tag = **p;
     if( params->tag != MBEDTLS_ASN1_OID