diff --git a/NEWS b/NEWS
index c7b481608be..08c46ee6561 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ PHP                                                                        NEWS
 - Curl:
   . Fix cloning of CURLOPT_POSTFIELDS when using the clone operator instead
     of the curl_copy_handle() function to clone a CurlHandle. (timwolla)
+  . Fix curl build failure on macOS+curl 8.16. (nielsdos)
 
 - Opcache:
   . Fixed bug GH-19669 (assertion failure in zend_jit_trace_type_to_info_ex).
diff --git a/ext/curl/interface.c b/ext/curl/interface.c
index 4b0391541f3..7cd8795c936 100644
--- a/ext/curl/interface.c
+++ b/ext/curl/interface.c
@@ -643,10 +643,10 @@ static int curl_fnmatch(void *ctx, const char *pattern, const char *string)
 /* }}} */
 
 /* {{{ curl_progress */
-static size_t curl_progress(void *clientp, double dltotal, double dlnow, double ultotal, double ulnow)
+static int curl_progress(void *clientp, double dltotal, double dlnow, double ultotal, double ulnow)
 {
 	php_curl *ch = (php_curl *)clientp;
-	size_t	rval = 0;
+	int rval = 0;
 
 #if PHP_CURL_DEBUG
 	fprintf(stderr, "curl_progress() called\n");
@@ -681,10 +681,10 @@ static size_t curl_progress(void *clientp, double dltotal, double dlnow, double
 /* }}} */
 
 /* {{{ curl_xferinfo */
-static size_t curl_xferinfo(void *clientp, curl_off_t dltotal, curl_off_t dlnow, curl_off_t ultotal, curl_off_t ulnow)
+static int curl_xferinfo(void *clientp, curl_off_t dltotal, curl_off_t dlnow, curl_off_t ultotal, curl_off_t ulnow)
 {
 	php_curl *ch = (php_curl *)clientp;
-	size_t rval = 0;
+	int rval = 0;
 
 #if PHP_CURL_DEBUG
 	fprintf(stderr, "curl_xferinfo() called\n");
@@ -1190,8 +1190,8 @@ static void _php_curl_set_default_options(php_curl *ch)
 {
 	char *cainfo;
 
-	curl_easy_setopt(ch->cp, CURLOPT_NOPROGRESS,        1);
-	curl_easy_setopt(ch->cp, CURLOPT_VERBOSE,           0);
+	curl_easy_setopt(ch->cp, CURLOPT_NOPROGRESS,        1L);
+	curl_easy_setopt(ch->cp, CURLOPT_VERBOSE,           0L);
 	curl_easy_setopt(ch->cp, CURLOPT_ERRORBUFFER,       ch->err.str);
 	curl_easy_setopt(ch->cp, CURLOPT_WRITEFUNCTION,     curl_write);
 	curl_easy_setopt(ch->cp, CURLOPT_FILE,              (void *) ch);
@@ -1199,8 +1199,8 @@ static void _php_curl_set_default_options(php_curl *ch)
 	curl_easy_setopt(ch->cp, CURLOPT_INFILE,            (void *) ch);
 	curl_easy_setopt(ch->cp, CURLOPT_HEADERFUNCTION,    curl_write_header);
 	curl_easy_setopt(ch->cp, CURLOPT_WRITEHEADER,       (void *) ch);
-	curl_easy_setopt(ch->cp, CURLOPT_DNS_CACHE_TIMEOUT, 120);
-	curl_easy_setopt(ch->cp, CURLOPT_MAXREDIRS, 20); /* prevent infinite redirects */
+	curl_easy_setopt(ch->cp, CURLOPT_DNS_CACHE_TIMEOUT, 120L);
+	curl_easy_setopt(ch->cp, CURLOPT_MAXREDIRS, 20L); /* prevent infinite redirects */
 
 	cainfo = INI_STR("openssl.cafile");
 	if (!(cainfo && cainfo[0] != '\0')) {
@@ -2216,7 +2216,7 @@ static zend_result _php_curl_setopt(php_curl *ch, zend_long option, zval *zvalue
 					/* no need to build the mime structure for empty hashtables;
 					   also works around https://github.com/curl/curl/issues/6455 */
 					curl_easy_setopt(ch->cp, CURLOPT_POSTFIELDS, "");
-					error = curl_easy_setopt(ch->cp, CURLOPT_POSTFIELDSIZE, 0);
+					error = curl_easy_setopt(ch->cp, CURLOPT_POSTFIELDSIZE, 0L);
 				} else {
 					return build_mime_structure_from_hash(ch, zvalue);
 				}
@@ -2249,7 +2249,7 @@ static zend_result _php_curl_setopt(php_curl *ch, zend_long option, zval *zvalue
 
 		case CURLOPT_POSTREDIR:
 			lval = zval_get_long(zvalue);
-			error = curl_easy_setopt(ch->cp, CURLOPT_POSTREDIR, lval & CURL_REDIR_POST_ALL);
+			error = curl_easy_setopt(ch->cp, CURLOPT_POSTREDIR, (long) (lval & CURL_REDIR_POST_ALL));
 			break;
 
 		/* the following options deal with files, therefore the open_basedir check
@@ -2289,11 +2289,11 @@ static zend_result _php_curl_setopt(php_curl *ch, zend_long option, zval *zvalue
 			if (zend_is_true(zvalue)) {
 				curl_easy_setopt(ch->cp, CURLOPT_DEBUGFUNCTION, curl_debug);
 				curl_easy_setopt(ch->cp, CURLOPT_DEBUGDATA, (void *)ch);
-				curl_easy_setopt(ch->cp, CURLOPT_VERBOSE, 1);
+				curl_easy_setopt(ch->cp, CURLOPT_VERBOSE, 1L);
 			} else {
 				curl_easy_setopt(ch->cp, CURLOPT_DEBUGFUNCTION, NULL);
 				curl_easy_setopt(ch->cp, CURLOPT_DEBUGDATA, NULL);
-				curl_easy_setopt(ch->cp, CURLOPT_VERBOSE, 0);
+				curl_easy_setopt(ch->cp, CURLOPT_VERBOSE, 0L);
 			}
 			break;