diff --git a/libs/pbd/semutils.cc b/libs/pbd/semutils.cc
index 0d8c603aa2..c9dea86589 100644
--- a/libs/pbd/semutils.cc
+++ b/libs/pbd/semutils.cc
@@ -105,7 +105,7 @@ int
 Semaphore::signal ()
 {
 	if (std::atomic_fetch_add_explicit (&_value, 1, std::memory_order_relaxed) < 0) {
-		while (syscall (__NR_futex, &_futex, FUTEX_WAKE_PRIVATE, 1, NULL, NULL, 0) < 1) {
+		while (syscall (SYS_futex, &_futex, FUTEX_WAKE_PRIVATE, 1, NULL, NULL, 0) < 1) {
 			sched_yield();
 		}
 	}
@@ -116,7 +116,7 @@ int
 Semaphore::wait ()
 {
 	if (std::atomic_fetch_sub_explicit (&_value, 1, std::memory_order_relaxed) <= 0) {
-		syscall(__NR_futex, &_futex, FUTEX_WAIT_PRIVATE, _futex, NULL, 0, 0);
+		syscall(SYS_futex, &_futex, FUTEX_WAIT_PRIVATE, _futex, NULL, 0, 0);
 	}
 	return 0;
 }
diff --git a/wscript b/wscript
index 2c68df86c1..8e60050b19 100644
--- a/wscript
+++ b/wscript
@@ -1358,8 +1358,16 @@ int main () { __int128 x = 0; return 0; }
         conf.env['NO_THREADED_WAVEVIEWS'] = True
     if not opts.no_futex_semaphore:
         if re.search ("linux", sys.platform) is not None and Options.options.dist_target != 'mingw':
-            conf.define('USE_FUTEX_SEMAPHORE', 1)
-            conf.env['USE_FUTEX_SEMAPHORE'] = True
+            have_sys_futex = conf.check_cc(
+                    msg="Checking for 'futex' syscall support",
+                    features  = 'c',
+                    mandatory = False,
+                    execute   = False,
+                    fragment = "#include <sys/syscall.h>\n#include <linux/futex.h>\nint main () { int x = SYS_futex | FUTEX_WAKE_PRIVATE; return 0; }")
+
+            if have_sys_futex:
+                    conf.define('USE_FUTEX_SEMAPHORE', 1)
+                    conf.env['USE_FUTEX_SEMAPHORE'] = True
 
     backends = opts.with_backends.split(',')