diff --git a/docs/README.md b/docs/README.md
index a92790b0..60582f66 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -2442,6 +2442,7 @@ mg_snprintf(buf, sizeof(buf), "%%-%3s", "a");           // %-  a
 
 ```c
 int64_t mg_to64(struct mg_str str);
+uint64_t mg_tou64(struct mg_str str);
 ```
 
 Parse 64-bit integer value held by string `s`.
diff --git a/mongoose.c b/mongoose.c
index 6b387925..870fc3ef 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -4049,6 +4049,19 @@ size_t mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
   return ret;
 }
 
+uint64_t mg_tou64(struct mg_str str) {
+  uint64_t result = 0;
+  size_t i = 0;
+  while (i < str.len && (str.ptr[i] == ' ' || str.ptr[i] == '\t')) i++;
+  while (i < str.len && str.ptr[i] >= '0' && str.ptr[i] <= '9') {
+    result *= 10;
+    result += (unsigned) (str.ptr[i] - '0');
+    MG_INFO(("[%.*s] %llu", (int) str.len, str.ptr, result));
+    i++;
+  }
+  return result;
+}
+
 int64_t mg_to64(struct mg_str str) {
   int64_t result = 0, neg = 1, max = 922337203685477570 /* INT64_MAX/10-10 */;
   size_t i = 0;
diff --git a/mongoose.h b/mongoose.h
index 459c1563..792497fe 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -632,6 +632,7 @@ size_t mg_asprintf(char **, size_t, const char *fmt, ...) PRINTF_LIKE(3, 4);
 size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap);
 int mg_check_ip_acl(struct mg_str acl, uint32_t remote_ip);
 int64_t mg_to64(struct mg_str str);
+uint64_t mg_tou64(struct mg_str str);
 size_t mg_lld(char *buf, int64_t val, bool is_signed, bool is_hex);
 
 
diff --git a/src/str.c b/src/str.c
index a699b69a..82cacba2 100644
--- a/src/str.c
+++ b/src/str.c
@@ -254,6 +254,19 @@ size_t mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
   return ret;
 }
 
+uint64_t mg_tou64(struct mg_str str) {
+  uint64_t result = 0;
+  size_t i = 0;
+  while (i < str.len && (str.ptr[i] == ' ' || str.ptr[i] == '\t')) i++;
+  while (i < str.len && str.ptr[i] >= '0' && str.ptr[i] <= '9') {
+    result *= 10;
+    result += (unsigned) (str.ptr[i] - '0');
+    MG_INFO(("[%.*s] %llu", (int) str.len, str.ptr, result));
+    i++;
+  }
+  return result;
+}
+
 int64_t mg_to64(struct mg_str str) {
   int64_t result = 0, neg = 1, max = 922337203685477570 /* INT64_MAX/10-10 */;
   size_t i = 0;
diff --git a/src/str.h b/src/str.h
index 2dc752ed..d702ae42 100644
--- a/src/str.h
+++ b/src/str.h
@@ -41,4 +41,5 @@ size_t mg_asprintf(char **, size_t, const char *fmt, ...) PRINTF_LIKE(3, 4);
 size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap);
 int mg_check_ip_acl(struct mg_str acl, uint32_t remote_ip);
 int64_t mg_to64(struct mg_str str);
+uint64_t mg_tou64(struct mg_str str);
 size_t mg_lld(char *buf, int64_t val, bool is_signed, bool is_hex);
diff --git a/test/unit_test.c b/test/unit_test.c
index bebe812b..e54c3b94 100644
--- a/test/unit_test.c
+++ b/test/unit_test.c
@@ -1499,6 +1499,11 @@ static void test_util(void) {
   ASSERT(mg_to64(mg_str("-9223372036854775809")) == 0);
   ASSERT(mg_to64(mg_str("9223372036854775800")) == 0);
   ASSERT(mg_to64(mg_str("9223372036854775700")) > 0);
+  ASSERT(mg_tou64(mg_str("0")) == 0);
+  ASSERT(mg_tou64(mg_str("123")) == 123);
+  ASSERT(mg_tou64(mg_str("")) == 0);
+  ASSERT(mg_tou64(mg_str("-")) == 0);
+  ASSERT(mg_tou64(mg_str("18446744073709551615")) == 18446744073709551615U);
 }
 
 static void test_crc32(void) {