diff --git a/libsrc/common/sleep.c b/libsrc/common/sleep.c
index a8fc4b32e..3a8e8e2e0 100644
--- a/libsrc/common/sleep.c
+++ b/libsrc/common/sleep.c
@@ -8,17 +8,20 @@
 
 
 
-#include <time.h>     
+#include <time.h>
 #include <unistd.h>
 
 
 
+/* We cannot implement this function without a working clock function */
+#if defined(CLOCKS_PER_SEC)
 unsigned __fastcall__ sleep (unsigned wait)
 {
     clock_t goal = clock () + ((clock_t) wait) * CLOCKS_PER_SEC;
     while ((long) (goal - clock ()) > 0) ;
     return 0;
 }
+#endif