diff --git a/compiler/res/prog8lib/cx16/syslib.p8 b/compiler/res/prog8lib/cx16/syslib.p8
index cefb3d982..63bc21a97 100644
--- a/compiler/res/prog8lib/cx16/syslib.p8
+++ b/compiler/res/prog8lib/cx16/syslib.p8
@@ -70,8 +70,10 @@ asmsub RDTIM16() -> uword @AY {
     ; --  like RDTIM() but only returning the lower 16 bits in AY for convenience. Also avoids ram bank issue for irqs.
     %asm {{
         phx
+        php
         sei
         jsr  cbm.RDTIM
+        plp
         cli
         pha
         txa
@@ -924,6 +926,7 @@ asmsub  set_rasterline(uword line @AY) {
     asmsub wait(uword jiffies @AY) {
         ; --- wait approximately the given number of jiffies (1/60th seconds) (N or N+1)
         ;     note: the system irq handler has to be active for this to work as it depends on the system jiffy clock
+        ;     note: this routine cannot be used from inside a irq handler
         %asm {{
             phx
             sta  P8ZP_SCRATCH_W1