--- a/promhttp/src/promhttp.c
+++ b/promhttp/src/promhttp.c
@@ -21,6 +21,13 @@
 
 prom_collector_registry_t *PROM_ACTIVE_REGISTRY;
 
+/* libmicrohttpd >= 0.9.71 declares the handler return type as enum MHD_Result */
+#if MHD_VERSION >= 0x00097100
+typedef enum MHD_Result promhttp_result_t;
+#else
+typedef int promhttp_result_t;
+#endif
+
 void promhttp_set_active_collector_registry(prom_collector_registry_t *active_registry) {
   if (!active_registry) {
     PROM_ACTIVE_REGISTRY = PROM_COLLECTOR_REGISTRY_DEFAULT;
@@ -29,32 +36,32 @@
   }
 }
 
-int promhttp_handler(void *cls, struct MHD_Connection *connection, const char *url, const char *method,
-                     const char *version, const char *upload_data, size_t *upload_data_size, void **con_cls) {
+promhttp_result_t promhttp_handler(void *cls, struct MHD_Connection *connection, const char *url, const char *method,
+                                   const char *version, const char *upload_data, size_t *upload_data_size, void **con_cls) {
   if (strcmp(method, "GET") != 0) {
     char *buf = "Invalid HTTP Method\n";
     struct MHD_Response *response = MHD_create_response_from_buffer(strlen(buf), (void *)buf, MHD_RESPMEM_PERSISTENT);
-    int ret = MHD_queue_response(connection, MHD_HTTP_BAD_REQUEST, response);
+    promhttp_result_t ret = MHD_queue_response(connection, MHD_HTTP_BAD_REQUEST, response);
     MHD_destroy_response(response);
     return ret;
   }
   if (strcmp(url, "/") == 0) {
     char *buf = "OK\n";
     struct MHD_Response *response = MHD_create_response_from_buffer(strlen(buf), (void *)buf, MHD_RESPMEM_PERSISTENT);
-    int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
+    promhttp_result_t ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
     MHD_destroy_response(response);
     return ret;
   }
   if (strcmp(url, "/metrics") == 0) {
     const char *buf = prom_collector_registry_bridge(PROM_ACTIVE_REGISTRY);
     struct MHD_Response *response = MHD_create_response_from_buffer(strlen(buf), (void *)buf, MHD_RESPMEM_MUST_FREE);
-    int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
+    promhttp_result_t ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
     MHD_destroy_response(response);
     return ret;
   }
   char *buf = "Bad Request\n";
   struct MHD_Response *response = MHD_create_response_from_buffer(strlen(buf), (void *)buf, MHD_RESPMEM_PERSISTENT);
-  int ret = MHD_queue_response(connection, MHD_HTTP_BAD_REQUEST, response);
+  promhttp_result_t ret = MHD_queue_response(connection, MHD_HTTP_BAD_REQUEST, response);
   MHD_destroy_response(response);
   return ret;
 }