diff --git a/parts/z80/stdio.asm b/parts/z80/stdio.asm
index 5f631fa..683e064 100644
--- a/parts/z80/stdio.asm
+++ b/parts/z80/stdio.asm
@@ -9,10 +9,10 @@
 
 ; *** VARIABLES ***
 ; Used to store formatted hex values just before printing it.
-STDIO_HEX_FMT	.equ	STDIO_RAMSTART
-STDIO_GETC	.equ	STDIO_HEX_FMT+2
-STDIO_PUTC	.equ	STDIO_GETC+2
-STDIO_RAMEND	.equ	STDIO_PUTC+2
+.equ	STDIO_HEX_FMT	STDIO_RAMSTART
+.equ	STDIO_GETC	STDIO_HEX_FMT+2
+.equ	STDIO_PUTC	STDIO_GETC+2
+.equ	STDIO_RAMEND	STDIO_PUTC+2
 
 ; Select the blockdev to use as stdio before calling this.
 stdioInit:
diff --git a/tools/tests/zasm/test6.asm b/tools/tests/zasm/test6.asm
index 0328e6c..953ad22 100644
--- a/tools/tests/zasm/test6.asm
+++ b/tools/tests/zasm/test6.asm
@@ -10,3 +10,7 @@
 .equ	BLOCKDEV_RAMSTART	ACIA_RAMEND
 .equ	BLOCKDEV_COUNT		1
 #include "blockdev.asm"
+.dw	aciaGetC, aciaPutC, 0, 0
+
+.equ	STDIO_RAMSTART	BLOCKDEV_RAMEND
+#include "stdio.asm"