diff --git a/apps/zasm/main.asm b/apps/zasm/main.asm
index 94aa6a2..d538298 100644
--- a/apps/zasm/main.asm
+++ b/apps/zasm/main.asm
@@ -56,7 +56,7 @@
 ; *** Code ***
 jp	zasmMain
 
-#include "util.asm"
+#include "util_z.asm"
 .equ	IO_RAMSTART	ZASM_RAMEND
 #include "io.asm"
 #include "tok.asm"
diff --git a/apps/zasm/util.asm b/apps/zasm/util_z.asm
similarity index 100%
rename from apps/zasm/util.asm
rename to apps/zasm/util_z.asm
diff --git a/tools/tests/unit/runtests.sh b/tools/tests/unit/runtests.sh
index 59f954a..5895a80 100755
--- a/tools/tests/unit/runtests.sh
+++ b/tools/tests/unit/runtests.sh
@@ -5,11 +5,12 @@ set -o pipefail
 
 SCAS=scas
 PARTS=../../../parts/z80
+ZASMDIR=../../../apps/zasm
 RUNBIN=../../emul/runbin/runbin
 
 for fn in *.asm; do
     echo "Running test ${fn}"
-    if ! ${SCAS} -I ${PARTS} -o - ${fn} | ${RUNBIN}; then
+    if ! ${SCAS} -I ${PARTS} -I ${ZASMDIR} -o - ${fn} | ${RUNBIN}; then
         echo "failed with code ${PIPESTATUS[1]}"
         exit 1
     fi
diff --git a/tools/tests/unit/test_parse_z.asm b/tools/tests/unit/test_parse_z.asm
new file mode 100644
index 0000000..a605228
--- /dev/null
+++ b/tools/tests/unit/test_parse_z.asm
@@ -0,0 +1,55 @@
+jp	test
+
+#include "core.asm"
+#include "parse.asm"
+#include "util_z.asm"
+#include "parse_z.asm"
+
+; mocks. aren't used in tests
+zasmIsFirstPass:
+symSelect:
+symFind:
+symGetVal:
+	jp	fail
+
+testNum:	.db 1
+
+s99:		.db "99", 0
+s0x99:		.db "0x99", 0
+sFoo:		.db "Foo", 0
+
+test:
+	ld	hl, 0xffff
+	ld	sp, hl
+
+	ld	hl, s99
+	call	parseLiteral
+	jp	nz, fail
+	ld	a, ixh
+	or	a
+	jp	nz, fail
+	ld	a, ixl
+	cp	99
+	jp	nz, fail
+	call	nexttest
+
+	ld	hl, sFoo
+	call	parseLiteral
+	jp	z, fail
+	call	nexttest
+
+	; success
+	xor	a
+	halt
+
+nexttest:
+	ld	a, (testNum)
+	inc	a
+	ld	(testNum), a
+	ret
+
+fail:
+	ld	a, (testNum)
+	halt
+
+