diff --git a/include/time.h b/include/time.h
index 4ee658da9..49d7e6870 100644
--- a/include/time.h
+++ b/include/time.h
@@ -83,46 +83,31 @@ extern struct _timezone {
 
 
 
-#if defined(__ATARI__)
-/* The clock depends on the video standard, so read it at runtime */
-unsigned _clocks_per_sec (void);
-#  define CLK_TCK               _clocks_per_sec()
-#  define CLOCKS_PER_SEC        _clocks_per_sec()
-#elif defined(__ATARI5200__)
-#  define CLK_TCK               60      /* POSIX */
-#  define CLOCKS_PER_SEC        60      /* ANSI */
+#if defined(__ATARI5200__)
+#  define CLOCKS_PER_SEC        60
 #elif defined(__ATMOS__)
-#  define CLK_TCK               100     /* POSIX */
-#  define CLOCKS_PER_SEC        100     /* ANSI */
+#  define CLOCKS_PER_SEC        100
 #elif defined(__CBM__)
 #  if defined(__CBM510__) || defined(__CBM610__)
 /* The 510/610 gets its clock from the AC current */
-#    define CLK_TCK             50      /* POSIX */
-#    define CLOCKS_PER_SEC      50      /* ANSI */
+#    define CLOCKS_PER_SEC      50
 #  else
-#    define CLK_TCK             60      /* POSIX */
-#    define CLOCKS_PER_SEC      60      /* ANSI */
+#    define CLOCKS_PER_SEC      60
 #  endif
 #elif defined(__NES__)
-#  define CLK_TCK               50      /* POSIX */
-#  define CLOCKS_PER_SEC        50      /* ANSI */
+#  define CLOCKS_PER_SEC        50
 #elif defined(__PCE__)
-#  define CLK_TCK               60      /* POSIX */
-#  define CLOCKS_PER_SEC        60      /* ANSI */
+#  define CLOCKS_PER_SEC        60
 #elif  defined(__GAMATE__)
-#  define CLK_TCK               135     /* POSIX */     /* FIXME */
-#  define CLOCKS_PER_SEC        135     /* ANSI */      /* FIXME */
+#  define CLOCKS_PER_SEC        135   /* FIXME */
 #elif  defined(__GEOS__)
-#  define CLK_TCK               1       /* POSIX */
-#  define CLOCKS_PER_SEC        1       /* ANSI */
-#elif defined(__LYNX__)
-/* The clock-rate depends on the video scan-rate;
-** so, read it at run-time.
-*/
-extern clock_t _clk_tck (void);
-#  define CLK_TCK               _clk_tck()
-#  define CLOCKS_PER_SEC        _clk_tck()
+#  define CLOCKS_PER_SEC        1
+#else
+/* Read the clock rate at runtime */
+clock_t _clocks_per_sec (void);
+#  define CLOCKS_PER_SEC        _clocks_per_sec()
 #endif
+#define CLK_TCK                 CLOCKS_PER_SEC
 #define CLOCK_REALTIME          0
 
 
@@ -149,6 +134,3 @@ int __fastcall__ clock_settime (clockid_t clock_id, const struct timespec *tp);
 /* End of time.h */
 
 #endif
-
-
-
diff --git a/libsrc/atari/clock.s b/libsrc/atari/clock.s
index e04416c18..853870520 100644
--- a/libsrc/atari/clock.s
+++ b/libsrc/atari/clock.s
@@ -3,7 +3,7 @@
 ; originally by Ullrich von Bassewitz and Sidney Cadot
 ;
 ; clock_t clock (void);
-; unsigned _clocks_per_sec (void);
+; clock_t _clocks_per_sec (void);
 ;
 
         .export         _clock, __clocks_per_sec
@@ -30,8 +30,10 @@
 
 .proc   __clocks_per_sec
 
-        ldx     #$00            ; Clear high byte of return value
-        lda     PAL             ; use hw register, PALNTS is only supported on XL/XE ROM
+        ldx     #$00            ; Clear byte 1 of return value
+        stx     sreg            ; Clear byte 2 of return value
+        stx     sreg+1          ; Clear byte 3 of return value
+        lda     PAL             ; Use hw register, PALNTS is only supported on XL/XE ROM
         and     #$0e
         bne     @NTSC
         lda     #50
diff --git a/libsrc/atari5200/clock.s b/libsrc/atari5200/clock.s
index f2ef85b0b..fff766093 100644
--- a/libsrc/atari5200/clock.s
+++ b/libsrc/atari5200/clock.s
@@ -2,7 +2,6 @@
 ; from Atari computer version by Christian Groessler, 2014
 ;
 ; clock_t clock (void);
-; unsigned _clocks_per_sec (void);
 ;
 
         .export         _clock
diff --git a/libsrc/lynx/clock.s b/libsrc/lynx/clock.s
index dbccb32cb..e29799df6 100644
--- a/libsrc/lynx/clock.s
+++ b/libsrc/lynx/clock.s
@@ -2,18 +2,14 @@
 ; 2003-04-13, Ullrich von Bassewitz
 ; 2012-02-06, Greg King
 ;
-; #include <time.h>
+; clock_t clock (void);
+; clock_t _clocks_per_sec (void);
 ;
-; typedef unsigned long int clock_t;
-; clock_t _clk_tck(void);
-; #define CLOCKS_PER_SEC _clk_tck()
-; clock_t clock(void);
-;
-; clk_tck()'s test-values are based on the numbers in "set_tv.s".
+; clocks_per_sec()'s test-values are based on the numbers in "set_tv.s".
 ; If you change the numbers there, then change them here, too.
 ;
 
-        .export         _clock, __clk_tck, clock_count
+        .export         _clock, __clocks_per_sec, clock_count
         .interruptor    update_clock, 2 ; (low priority)
         .constructor    init_clock
 
@@ -42,7 +38,7 @@
 ;-----------------------------------------------------------------------------
 ; Return the number of clock ticks in one second.
 ;
-__clk_tck:
+__clocks_per_sec:
         ldx     #$00            ; >50, >60, >75
         ldy     PBKUP
         lda     #<75