diff --git a/nasal.h b/nasal.h
index d8c6ab5..d8537cf 100644
--- a/nasal.h
+++ b/nasal.h
@@ -20,6 +20,8 @@
 #include <queue>
 #include <vector>
 #include <unordered_map>
+#include <thread>
+#include <chrono>
 
 #include <sys/stat.h>
 #include <fcntl.h>
diff --git a/nasal_builtin.h b/nasal_builtin.h
index 13450a0..604c6b2 100644
--- a/nasal_builtin.h
+++ b/nasal_builtin.h
@@ -1037,7 +1037,7 @@ nasal_ref builtin_sleep(nasal_ref* local,nasal_gc& gc)
     nasal_ref val=local[1];
     if(val.type!=vm_num)
         return builtin_err("sleep","\"duration\" must be number");
-    usleep((useconds_t)(val.num()*1e6));
+    std::this_thread::sleep_for(std::chrono::microseconds(int64_t(val.num()*1e6)));
     return nil;
 }
 nasal_ref builtin_pipe(nasal_ref* local,nasal_gc& gc)