diff --git a/common/attrlist.c b/common/attrlist.c
index e4c8ad67..1ca52537 100644
--- a/common/attrlist.c
+++ b/common/attrlist.c
@@ -284,6 +284,13 @@ static struct attr *attrDeleteRange(struct attrlist *alist, struct attr *a, size
 	return a->next;
 }
 
+static int boolsEqual(struct attr *attr, uiAttributeSpec *spec)
+{
+	if (attr->spec.Value == 0 && spec->Value == 0)
+		return 1;
+	return attr->spec.Value != 0 && spec->Value != 0;
+}
+
 static int specsIdentical(struct attr *attr, uiAttributeSpec *spec)
 {
 	if (attr->spec.Type != spec->Type)
@@ -303,7 +310,7 @@ static int specsIdentical(struct attr *attr, uiAttributeSpec *spec)
 			attr->spec.B == spec->B &&
 			attr->spec.A == spec->A;
 	case uiAttributeVerticalForms:
-		return 1;
+		return boolsEqual(attr, spec);
 	// TODO
 	}
 	// handles the rest
diff --git a/darwin/attrstr.m b/darwin/attrstr.m
index 07663838..051bec16 100644
--- a/darwin/attrstr.m
+++ b/darwin/attrstr.m
@@ -132,7 +132,10 @@ static int processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t
 		Block_release(block);
 		break;
 	case uiAttributeVerticalForms:
-		CFAttributedStringSetAttribute(p->mas, range, kCTVerticalFormsAttributeName, kCFBooleanTrue);
+		if (spec->Value != 0)
+			CFAttributedStringSetAttribute(p->mas, range, kCTVerticalFormsAttributeName, kCFBooleanTrue);
+		else
+			CFAttributedStringSetAttribute(p->mas, range, kCTVerticalFormsAttributeName, kCFBooleanFalse);
 		break;
 	// TODO
 	}
diff --git a/examples/drawtext/attributes.c b/examples/drawtext/attributes.c
index 7599dcfc..1aa74a72 100644
--- a/examples/drawtext/attributes.c
+++ b/examples/drawtext/attributes.c
@@ -96,6 +96,7 @@ static void setupAttributedString(void)
 	end = start + strlen(next);
 	uiAttributedStringAppendUnattributed(attrstr, next);
 	spec.Type = uiAttributeVerticalForms;
+	spec.Value = 1;
 	uiAttributedStringSetAttribute(attrstr, &spec, start, end);
 
 	uiAttributedStringAppendUnattributed(attrstr, " (which you can draw rotated for proper vertical text)");
diff --git a/ui_attrstr.h b/ui_attrstr.h
index 6d6021d2..f5506fa0 100644
--- a/ui_attrstr.h
+++ b/ui_attrstr.h
@@ -9,7 +9,7 @@ _UI_ENUM(uiAttribute) {
 	uiAttributeStretch,
 	uiAttributeColor,			// use R, G, B, A
 	uiAttributeBackground,		// use R, G, B, A
-	uiAttributeVerticalForms,		// no parameter
+	uiAttributeVerticalForms,		// 0 = off, nonzero = 1
 	// TODO
 	// TODO uiAttributeSystem,
 	// TODO uiAttributeCustom,