diff --git a/src/pk/asn1/der/object_identifier/der_decode_object_identifier.c b/src/pk/asn1/der/object_identifier/der_decode_object_identifier.c
index f49786272..23dcf770f 100644
--- a/src/pk/asn1/der/object_identifier/der_decode_object_identifier.c
+++ b/src/pk/asn1/der/object_identifier/der_decode_object_identifier.c
@@ -71,8 +71,13 @@ int der_decode_object_identifier(const unsigned char *in,    unsigned long  inle
             y++;
          } else {
             if (y == 0) {
-               words[0] = t / 40;
-               words[1] = t % 40;
+               if (t <= 79) {
+                  words[0] = t / 40;
+                  words[1] = t % 40;
+               } else {
+                  words[0] = 2;
+                  words[1] = t - 80;
+               }
                y = 2;
             } else {
                words[y++] = t;
diff --git a/src/pk/asn1/der/object_identifier/der_length_object_identifier.c b/src/pk/asn1/der/object_identifier/der_length_object_identifier.c
index cc22a3c9b..e6cff37a4 100644
--- a/src/pk/asn1/der/object_identifier/der_length_object_identifier.c
+++ b/src/pk/asn1/der/object_identifier/der_length_object_identifier.c
@@ -48,8 +48,8 @@ int der_length_object_identifier(const unsigned long *words, unsigned long nword
       return CRYPT_INVALID_ARG;
    }
 
-   /* word1 = 0,1,2,3 and word2 0..39 */
-   if (words[0] > 3 || (words[0] < 2 && words[1] > 39)) {
+   /* word1 = 0,1,2 and word2 0..39 */
+   if (words[0] > 2 || (words[0] < 2 && words[1] > 39)) {
       return CRYPT_INVALID_ARG;
    }
 
diff --git a/tests/der_test.c b/tests/der_test.c
index 8ad5e34a4..4f15b2839 100644
--- a/tests/der_test.c
+++ b/tests/der_test.c
@@ -673,6 +673,34 @@ static void der_set_test(void)
 
 */
 
+static void _der_oid_test(void)
+{
+   static const unsigned char oid_x690_8_19_5_example[] = { 0x06, 0x03, 0x88, 0x37, 0x03 };
+   unsigned long len, oid[3];
+   unsigned char buf[64];
+
+   ltc_asn1_list *decoded_list, static_list[1];
+
+   len = sizeof(oid_x690_8_19_5_example);
+   DO(der_decode_sequence_flexi(oid_x690_8_19_5_example, &len, &decoded_list));
+
+   LTC_SET_ASN1(static_list, 0, LTC_ASN1_OBJECT_IDENTIFIER, (void *)decoded_list->data, decoded_list->size);
+   len = sizeof(buf);
+   DO(der_encode_object_identifier(decoded_list->data, decoded_list->size, buf, &len));
+   der_sequence_free(decoded_list);
+
+   DO(do_compare_testvector(buf, len, oid_x690_8_19_5_example, sizeof(oid_x690_8_19_5_example), "OID X6.90 Ch. 8.19.5 Example", 0));
+
+   oid[0] = 3;
+   oid[1] = 4;
+   oid[2] = 5;
+
+   len = sizeof(buf);
+   SHOULD_FAIL(der_encode_object_identifier(oid, 3, buf, &len));
+   len = sizeof(buf);
+   SHOULD_FAIL(der_length_object_identifier(oid, 3, &len));
+}
+
 static void der_flexi_test(void)
 {
    static const char printable_str[]    = "printable";
@@ -1589,6 +1617,8 @@ int der_test(void)
 
    der_cacert_test();
 
+   _der_oid_test();
+
    y = 0xffffff00;
 #if ULONG_MAX == ULLONG_MAX
    y <<= 32;