--- a/thermferm/thermferm.c	Sat May 04 15:43:37 2024 +0200
+++ b/thermferm/thermferm.c	Sat May 04 17:37:47 2024 +0200
@@ -118,6 +118,16 @@
 extern char		*state;
 
 
+#ifndef HAVE_GETTID
+/*
+ * Wrapper for older systems
+ */
+pid_t gettid(void)
+{
+    return (pid_t)syscall(__NR_gettid);
+}
+#endif
+
 
 void help(void)
 {