diff --git a/src/parse/properties/utils.c b/src/parse/properties/utils.c
index 42daa45..9e4ef08 100644
--- a/src/parse/properties/utils.c
+++ b/src/parse/properties/utils.c
@@ -710,7 +710,7 @@ static bool parse_hsl(
 			return false;
 		}
 
-		if (token->type != CSS_TOKEN_NUMBER) {
+		if (token->type == CSS_TOKEN_NUMBER) {
 			alpha = FIXTOINT(FMUL(alpha, F_255));
 		} else {
 			alpha = FIXTOINT(FDIV(FMUL(alpha, F_255), F_100));
@@ -890,7 +890,7 @@ static bool parse_hwb(
 			return false;
 		}
 
-		if (token->type != CSS_TOKEN_NUMBER) {
+		if (token->type == CSS_TOKEN_NUMBER) {
 			alpha = FIXTOINT(FMUL(alpha, F_255));
 		} else {
 			alpha = FIXTOINT(FDIV(FMUL(alpha, F_255), F_100));
diff --git a/test/data/parse/INDEX b/test/data/parse/INDEX
index ced33a3..65cad10 100644
--- a/test/data/parse/INDEX
+++ b/test/data/parse/INDEX
@@ -7,5 +7,6 @@ selectors.dat		Selectors
 atrules.dat		@-rules
 colours.dat		Colour values
 colours-hsl.dat		HSL Colour values
+colours-hwb.dat		HWB Colour values
 nth.dat			:nth-* expressions
 properties.dat		Properties
diff --git a/test/data/parse/colours-hsl.dat b/test/data/parse/colours-hsl.dat
index 2a98ba9..b6e9223 100644
--- a/test/data/parse/colours-hsl.dat
+++ b/test/data/parse/colours-hsl.dat
@@ -9,6 +9,136 @@
 |   0x02000018 0xffff0000
 #reset
 
+#data
+* { color: hsl(0 100% 50%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xffff0000
+#reset
+
+#data
+* { color: hsl(0, 100%, 50%, 100%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xffff0000
+#reset
+
+#data
+* { color: hsl(0 100% 50% / 0.5) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7fff0000
+#reset
+
+#data
+* { color: hsl(0 100% 50%/0.5) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7fff0000
+#reset
+
+#data
+* { color: hsl(0 100% 50/0.5) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7fff0000
+#reset
+
+#data
+* { color: hsl(0 100% 50% / 50%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7fff0000
+#reset
+
+#data
+* { color: hsla(0 100% 50% / 50%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7fff0000
+#reset
+
+#data
+* { color: hsl(0 100% 50% / 1) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xffff0000
+#reset
+
+#data
+* { color: hsl(0 100% 50%, 1) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hsl(0 , 100% , 50% , 1) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xffff0000
+#reset
+
+#data
+* { color: hsla(0 , 100% , 50% , 1) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xffff0000
+#reset
+
+#data
+* { color: hsl(0 , 100% , 50% , 1 ,) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hsl(0 , 100% , 50% ,) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hsl(0,100%,50%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xffff0000
+#reset
+
+#data
+* { color: hsl(0, 100% 50%) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hsl(0 100%, 50%) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hsla(0 100%, 50%) }
+#errors
+#expected
+| 1 *
+#reset
+
 ## yellow
 #data
 * { color: hsl(60, 100%, 50%) }
@@ -18,6 +148,15 @@
 |   0x02000018 0xffffff00
 #reset
 
+## yellow
+#data
+* { color: hsl(60deg, 100%, 50%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xffffff00
+#reset
+
 ## green
 #data
 * { color: hsl(120, 100%, 50%) }
diff --git a/test/data/parse/colours-hwb.dat b/test/data/parse/colours-hwb.dat
new file mode 100644
index 0000000..2dac90d
--- /dev/null
+++ b/test/data/parse/colours-hwb.dat
@@ -0,0 +1,136 @@
+## simple hwb color values
+
+## red
+#data
+* { color: hwb(0, 100%, 50%) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwba(0 100% 50% / 50%) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwb(0 100% 50%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xffaaaaaa
+#reset
+
+#data
+* { color: hwb(0, 100%, 50%, 100%) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwb(0 100%, 50%, 100%) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwb(0 100%, 50%) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwb(0 100% 50% 100%) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwb(0 100% 50% / 0.5) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7faaaaaa
+#reset
+
+#data
+* { color: hwb(0 100% 50% / 50%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7faaaaaa
+#reset
+
+#data
+* { color: hwb(0 100% 50% / 1) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xffaaaaaa
+#reset
+
+#data
+* { color: hwb(0 100% 50%, 1) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwb(0 , 100% , 50% , 1) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwb(0 , 100% , 50% , 1 ,) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwb(0 , 100% , 50% ,) }
+#errors
+#expected
+| 1 *
+#reset
+
+#data
+* { color: hwb(267 19% 60%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0xff483066
+#reset
+
+#data
+* { color: hwb(267 19% 60% / 0.5) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7f483066
+#reset
+
+#data
+* { color: hwb(267 19% 60% / 50%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7f483066
+#reset
+
+#data
+* { color: hwb(267 19% 60%/50%) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7f483066
+#reset
diff --git a/test/data/parse/colours.dat b/test/data/parse/colours.dat
index 312845e..15dae8b 100644
--- a/test/data/parse/colours.dat
+++ b/test/data/parse/colours.dat
@@ -80,6 +80,14 @@
 |   0x02000018 0x7f0000ff
 #reset
 
+#data
+* { color: rgb(none 0% 255/0.5) }
+#errors
+#expected
+| 1 *
+|   0x02000018 0x7f0000ff
+#reset
+
 #data
 * { color: rgb(none 0% 255 none) }
 #errors
diff --git a/test/parse-auto.c b/test/parse-auto.c
index 5f926e3..18fae0e 100644
--- a/test/parse-auto.c
+++ b/test/parse-auto.c
@@ -553,10 +553,14 @@ bool validate_rule_selector(css_rule_selector *s, exp_entry *e)
 				printf("FAIL Bytecode differs\n"
 				       "    Bytecode differs at %u\n	",
 					(int) i);
-				while (i < e->bcused) {
-					printf("%.2x ",
-						((uint8_t *) s->style->bytecode)[i]);
-					i++;
+				for (unsigned a = 0; a < e->bcused; a++) {
+					if (a == i) {
+						printf("[%.2x] ",
+							((uint8_t *) s->style->bytecode)[a]);
+					} else {
+						printf("%.2x ",
+							((uint8_t *) s->style->bytecode)[a]);
+					}
 				}
 				printf("\n");
 				return true;