diff --git a/crypto/asn1/asn1_test.cc b/crypto/asn1/asn1_test.cc
index 1044f7b..d2adbba 100644
--- a/crypto/asn1/asn1_test.cc
+++ b/crypto/asn1/asn1_test.cc
@@ -21,6 +21,11 @@
 #include "../test/scoped_types.h"
 
 
+// kTag128 is an ASN.1 structure with a universal tag with number 128.
+static const uint8_t kTag128[] = {
+    0x1f, 0x81, 0x00, 0x01, 0x00,
+};
+
 // kTag258 is an ASN.1 structure with a universal tag with number 258.
 static const uint8_t kTag258[] = {
     0x1f, 0x82, 0x02, 0x01, 0x00,
@@ -29,6 +34,12 @@
 static_assert(V_ASN1_NEG_INTEGER == 258,
               "V_ASN1_NEG_INTEGER changed. Update kTag258 to collide with it.");
 
+// kTagOverflow is an ASN.1 structure with a universal tag with number 2^35-1,
+// which will not fit in an int.
+static const uint8_t kTagOverflow[] = {
+    0x1f, 0xff, 0xff, 0xff, 0xff, 0x7f, 0x01, 0x00,
+};
+
 bool TestLargeTags() {
   const uint8_t *p = kTag258;
   ScopedASN1_TYPE obj(d2i_ASN1_TYPE(NULL, &p, sizeof(kTag258)));
@@ -36,6 +47,25 @@
     fprintf(stderr, "Parsed value with illegal tag (type = %d).\n", obj->type);
     return false;
   }
+  ERR_clear_error();
+
+  p = kTagOverflow;
+  obj.reset(d2i_ASN1_TYPE(NULL, &p, sizeof(kTagOverflow)));
+  if (obj) {
+    fprintf(stderr, "Parsed value with tag overflow (type = %d).\n", obj->type);
+    return false;
+  }
+  ERR_clear_error();
+
+  p = kTag128;
+  obj.reset(d2i_ASN1_TYPE(NULL, &p, sizeof(kTag128)));
+  if (!obj || obj->type != 128 || obj->value.asn1_string->length != 1 ||
+      obj->value.asn1_string->data[0] != 0) {
+    fprintf(stderr, "Failed to parse value with tag 128.\n");
+    ERR_print_errors_fp(stderr);
+    return false;
+  }
+
   return true;
 }