diff --git a/src/url.cpp b/src/url.cpp
index c4e1c487e..32d81fd8c 100644
--- a/src/url.cpp
+++ b/src/url.cpp
@@ -65,7 +65,7 @@ bool url::parse_ipv4(std::string_view input) {
       // We have the last value.
       // At this stage, ipv4 contains digit_count*8 bits.
       // So we have 32-digit_count*8 bits left.
-      if (segment_result > (uint64_t(1) << (32 - digit_count * 8))) {
+      if (segment_result >= (uint64_t(1) << (32 - digit_count * 8))) {
         return is_valid = false;
       }
       ipv4 <<= (32 - digit_count * 8);
diff --git a/src/url_aggregator.cpp b/src/url_aggregator.cpp
index 2b761ad34..e9a3a1546 100644
--- a/src/url_aggregator.cpp
+++ b/src/url_aggregator.cpp
@@ -898,7 +898,7 @@ bool url_aggregator::parse_ipv4(std::string_view input) {
       // We have the last value.
       // At this stage, ipv4 contains digit_count*8 bits.
       // So we have 32-digit_count*8 bits left.
-      if (segment_result > (uint64_t(1) << (32 - digit_count * 8))) {
+      if (segment_result >= (uint64_t(1) << (32 - digit_count * 8))) {
         return is_valid = false;
       }
       ipv4 <<= (32 - digit_count * 8);
diff --git a/tests/basic_tests.cpp b/tests/basic_tests.cpp
index 7a3bd8a42..4f44badc8 100644
--- a/tests/basic_tests.cpp
+++ b/tests/basic_tests.cpp
@@ -396,3 +396,9 @@ TYPED_TEST(basic_tests, nodejs_50235) {
   ASSERT_EQ(out->get_href(), "http://test.com:5/path?param=1");
   SUCCEED();
 }
+
+// https://github.com/nodejs/node/issues/51514
+TYPED_TEST(basic_tests, nodejs_51514) {
+  auto out = ada::parse<TypeParam>("http://1.1.1.256");
+  ASSERT_FALSE(out);
+}