diff --git a/compiler/res/prog8lib/conv.p8 b/compiler/res/prog8lib/conv.p8
index 131aec67b..2e4f197b9 100644
--- a/compiler/res/prog8lib/conv.p8
+++ b/compiler/res/prog8lib/conv.p8
@@ -28,30 +28,29 @@ asmsub  str_ub  (ubyte value @ A) clobbers(X) -> str @AY  {
 	%asm {{
 		ldy  #0
 		sty  P8ZP_SCRATCH_B1
-		jsr  conv.ubyte2decimal
-_output_byte_digits
+		jsr  ubyte2decimal     ; result in Y/A/X (100s, 10s, 1s).
         ; hundreds?
 		cpy  #'0'
 		beq  +
-		pha
-		tya
-		ldy  P8ZP_SCRATCH_B1
-		sta  string_out,y
-		pla
-		inc  P8ZP_SCRATCH_B1
+		sty  string_out
+		sta  string_out+1
+		stx  string_out+2
+		lda  #0
+		sta  string_out+3
+		jmp  _done
 		; tens?
-+		ldy  P8ZP_SCRATCH_B1
-        cmp  #'0'
++		cmp  #'0'
 		beq  +
-		sta  string_out,y
-		iny
+		sta  string_out
+		stx  string_out+1
+		lda  #0
+		sta  string_out+2
+		jmp  _done
 +       ; ones.
-        txa
-        sta  string_out,y
-        iny
-        lda  #0
-        sta  string_out,y
-        lda  #<string_out
+        stx  string_out
+		lda  #0
+		sta  string_out+1
+_done   lda  #<string_out
         ldy  #>string_out
         rts
 	}}
@@ -60,17 +59,39 @@ _output_byte_digits
 asmsub  str_b  (byte value @ A) clobbers(X) -> str @AY  {
 	; ---- convert the byte in A in decimal string form, without left padding 0s
 	%asm {{
-        ldy  #0
-        sty  P8ZP_SCRATCH_B1
+	    ldy  #0
         cmp  #0
         bpl  +
-        pha
-        lda  #'-'
-        sta  string_out
-        inc  P8ZP_SCRATCH_B1
-        pla
-+	    jsr  conv.byte2decimal
-        bra  str_ub._output_byte_digits
+        ldy  #'-'
+        sty  string_out
+        ldy  #1
++       sty  P8ZP_SCRATCH_REG
+   	    jsr  conv.byte2decimal      ; result in Y/A/X (100s, 10s, 1s).  and in uword2decimal.decHundreds, decTens, decOnes.
+        ; hundreds?
+		cpy  #'0'
+		bne  _out_hundreds
+		ldy  P8ZP_SCRATCH_REG
+        cmp  #'0'
+        bne  _out_tens
+        beq  _out_ones
+_out_hundreds
+		ldy  P8ZP_SCRATCH_REG
+		lda  uword2decimal.decHundreds
+		sta  string_out,y
+		iny
+_out_tens
+		lda  uword2decimal.decTens
+		sta  string_out,y
+		iny
+_out_ones
+		lda  uword2decimal.decOnes
+        sta  string_out,y
+        iny
+        lda  #0
+        sta  string_out,y
+        lda  #<string_out
+        ldy  #>string_out
+   	    rts
 	}}
 }
 
diff --git a/examples/test.p8 b/examples/test.p8
index 4a8e65513..e20871ced 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -1,27 +1,21 @@
+; conv_bug.p8
 %import textio
+%import conv
 %zeropage basicsafe
 %option no_sysinit
 
 main {
     sub start() {
-        uword[3] uwarray = [1111,2222,3333]
-        uword[3] @split uwarray_s = [1111,2222,3333]
-        ubyte[3] array = [11,22,33]
-
-        rol(array[1])
-        array[1] <<=1
-        ror(array[1])
-        array[1] >>=1
-
-        rol(uwarray[1])
-        uwarray[1] <<=1
-        ror(uwarray[1])
-        uwarray[1] >>=1
-
-        rol(uwarray_s[1])
-        uwarray_s[1] *=3
-        ror(uwarray_s[1])
-        uwarray_s[1] *=3
+        ubyte num8 = 99
+        ubyte i
+        ubyte jj = 99
 
+        for i in 0 to 255 {
+            txt.print(conv.str_ub(i))
+            txt.spc()
+            txt.print(conv.str_b(i as byte))
+            txt.chrout(';')
+            txt.nl()
+        }
     }
 }