diff --git a/src/hsts.cc b/src/hsts.cc
index aa00aa4..196ba15 100644
--- a/src/hsts.cc
+++ b/src/hsts.cc
@@ -146,7 +146,7 @@ static std::string Hsts_parse_attr(const char **header_str)
 /**
  * Get the value in *header_str.
  */
-static char *Hsts_parse_value(const char **header_str)
+static std::string Hsts_parse_value(const char **header_str)
 {
    uint_t len;
    const char *str;
@@ -167,7 +167,7 @@ static char *Hsts_parse_value(const char **header_str)
       str = *header_str;
       len = 0;
    }
-   return dStrndup(str, len);
+   return std::string{ str, str + len };
 }
 
 /**
@@ -199,22 +199,20 @@ void a_Hsts_set(const char *header, const DilloUrl *url)
    /* Iterate until there is nothing left of the string */
    while (*header) {
       std::string attr;
-      char *value;
 
       /* Get attribute */
       attr = Hsts_parse_attr(&header);
 
       /* Get the value for the attribute and store it */
       if (dStrAsciiCasecmp(attr.c_str(), "max-age") == 0) {
-         value = Hsts_parse_value(&header);
-         if (isdigit(*value)) {
+         auto value = Hsts_parse_value(&header);
+         if (isdigit(*value.c_str())) {
             errno = 0;
-            max_age = strtol(value, NULL, 10);
+            max_age = strtol(value.c_str(), NULL, 10);
             if (errno == ERANGE)
                max_age = INT_MAX;
             max_age_valid = TRUE;
          }
-         dFree(value);
       } else if (dStrAsciiCasecmp(attr.c_str(), "includeSubDomains") == 0) {
          subdomains = TRUE;
          Hsts_eat_value(&header);