diff --git a/darwin/attrstr.h b/darwin/attrstr.h
index 02a3418d..0c2c31f4 100644
--- a/darwin/attrstr.h
+++ b/darwin/attrstr.h
@@ -89,3 +89,5 @@ extern CFAttributedStringRef uiprivAttributedStringToCFAttributedString(uiDrawTe
 - (id)initWithStart:(size_t)s end:(size_t)e r:(double)red g:(double)green b:(double)blue a:(double)alpha;
 - (void)draw:(CGContextRef)c layout:(uiDrawTextLayout *)layout at:(double)x y:(double)y utf8Mapping:(const size_t *)u16tou8;
 @end
+
+CGColorRef mkcolor(double r, double g, double b, double a);
diff --git a/darwin/attrstr.m b/darwin/attrstr.m
index 36a180be..b861e736 100644
--- a/darwin/attrstr.m
+++ b/darwin/attrstr.m
@@ -271,26 +271,6 @@ static void addFontAttributeToRange(struct foreachParams *p, size_t start, size_
 	}
 }
 
-static CGColorRef mkcolor(double r, double g, double b, double a)
-{
-	CGColorSpaceRef colorspace;
-	CGColorRef color;
-	CGFloat components[4];
-
-	// TODO we should probably just create this once and recycle it throughout program execution...
-	colorspace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
-	if (colorspace == NULL) {
-		// TODO
-	}
-	components[0] = r;
-	components[1] = g;
-	components[2] = b;
-	components[3] = a;
-	color = CGColorCreate(colorspace, components);
-	CFRelease(colorspace);
-	return color;
-}
-
 static void addBackgroundAttribute(struct foreachParams *p, size_t start, size_t end, double r, double g, double b, double a)
 {
 	uiprivDrawTextBackgroundParams *dtb;
@@ -308,6 +288,7 @@ static void addBackgroundAttribute(struct foreachParams *p, size_t start, size_t
 		return;
 	}
 
+	CFAttributedStringSetAttribute(p->mas, CFRangeMake(start, end - start), (CFStringRef)@"FORCE_RUN", [NSString stringWithFormat:@"%lu %lu", start, end]);
 	dtb = [[uiprivDrawTextBackgroundParams alloc] initWithStart:start end:end r:r g:g b:b a:a];
 	[p->backgroundParams addObject:dtb];
 	[dtb release];
diff --git a/darwin/drawtext.m b/darwin/drawtext.m
index c04b402b..3799ddde 100644
--- a/darwin/drawtext.m
+++ b/darwin/drawtext.m
@@ -3,6 +3,8 @@
 #import "draw.h"
 #import "attrstr.h"
 
+#define inRange(min, x, max) ((min) <= (x) && (x) <= (max))
+
 // problem: for a CTFrame made from an empty string, the CTLine array will be empty, and we will crash when doing anything requiring a CTLine
 // solution: for those cases, maintain a separate framesetter just for computing those things
 // in the usual case, the separate copy will just be identical to the regular one, with extra references to everything within
@@ -18,8 +20,41 @@
 - (void)draw:(uiDrawContext *)c textLayout:(uiDrawTextLayout *)tl at:(double)x y:(double)y;
 - (void)returnWidth:(double *)width height:(double *)height;
 - (CFArrayRef)lines;
+- (void)lineOrigins:(CFRange)range origins:(CGPoint*)origins;
 @end
 
+struct uiDrawTextLayout {
+	uiprivTextFrame *frame;
+	uiprivTextFrame *forLines;
+	BOOL empty;
+
+	// for converting CFAttributedString indices from/to byte offsets
+	size_t *u8tou16;
+	size_t nUTF8;
+	size_t *u16tou8;
+	size_t nUTF16;
+};
+
+CGColorRef mkcolor(double r, double g, double b, double a)
+{
+	CGColorSpaceRef colorspace;
+	CGColorRef color;
+	CGFloat components[4];
+
+	// TODO we should probably just create this once and recycle it throughout program execution...
+	colorspace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
+	if (colorspace == NULL) {
+		// TODO
+	}
+	components[0] = r;
+	components[1] = g;
+	components[2] = b;
+	components[3] = a;
+	color = CGColorCreate(colorspace, components);
+	CFRelease(colorspace);
+	return color;
+}
+
 @implementation uiprivDrawTextBackgroundParams
 
 - (id)initWithStart:(size_t)s end:(size_t)e r:(double)red g:(double)green b:(double)blue a:(double)alpha
@@ -38,7 +73,58 @@
 
 - (void)draw:(CGContextRef)c layout:(uiDrawTextLayout *)layout at:(double)x y:(double)y utf8Mapping:(const size_t *)u16tou8
 {
-	// TODO
+	long startI = u16tou8[self->start];
+	long endI = u16tou8[self->end];
+
+	CGColorRef color = mkcolor(self->r, self->g, self->b, self->a);
+
+	double frameHeight;
+	[layout->frame returnWidth:NULL height:&frameHeight];
+
+	CFArrayRef lines = [layout->frame lines];
+	size_t numOfLines = CFArrayGetCount(lines);
+	CGPoint lineOrigins[numOfLines];
+
+	[layout->frame lineOrigins:CFRangeMake(0, numOfLines) origins:lineOrigins];
+	for (size_t i = 0; i < numOfLines; i++) {
+		CTLineRef line = CFArrayGetValueAtIndex(lines, i);
+		CFRange lr = CTLineGetStringRange(line);
+		CFIndex lineStart = lr.location;
+		CFIndex lineEnd = lineStart + lr.length;
+		if (inRange(startI, lineStart, endI) ||
+			inRange(startI, lineEnd, endI) || 
+			inRange(lineStart, startI, lineEnd) ||
+			inRange(lineStart, endI, lineEnd)) {
+
+			CFArrayRef glyphruns = CTLineGetGlyphRuns(line);
+			size_t numOfRuns = CFArrayGetCount(glyphruns);
+			for (size_t j = 0; j < numOfRuns; j++) {
+				// from https://stackoverflow.com/a/5341819/2352201
+				CTRunRef run = CFArrayGetValueAtIndex(glyphruns, j);
+				CFRange runRange = CTRunGetStringRange(run);
+				CFIndex runStart = runRange.location;
+				CFIndex runEnd = runStart + runRange.length;
+				if (startI <= runStart && runEnd <= endI) {
+					CGRect rect;
+
+					CGFloat ascent; //height above the baseline
+					CGFloat descent; //height below the baseline
+					rect.size.width = CTRunGetTypographicBounds(run, CFRangeMake(0, 0), &ascent, &descent, NULL);
+					rect.size.height = ascent + descent;
+
+					rect.origin.x = lineOrigins[i].x + x + CTLineGetOffsetForStringIndex(line, runRange.location, NULL);
+					rect.origin.y = (frameHeight - lineOrigins[i].y) + y - ascent + descent;
+					rect.origin.y -= descent;
+
+					CGContextAddRect(c, rect);
+					CGContextSetFillColorWithColor(c, color);
+					CGContextDrawPath(c, kCGPathFill);
+				}
+			}
+		}
+	}
+
+	CFRelease(color);
 }
 
 @end
@@ -109,7 +195,7 @@
 	textMatrix = CGContextGetTextMatrix(c->c);
 
 	for (dtb in self->backgroundParams)
-		/* TODO */;
+		[dtb draw:c->c layout:tl at:x y:y utf8Mapping:tl->u16tou8];
 
 	// Core Text doesn't draw onto a flipped view correctly; we have to pretend it was unflipped
 	// see the iOS bits of the first example at https://developer.apple.com/library/mac/documentation/StringsTextFonts/Conceptual/CoreText_Programming/LayoutOperations/LayoutOperations.html#//apple_ref/doc/uid/TP40005533-CH12-SW1 (iOS is naturally flipped)
@@ -147,20 +233,13 @@
 	return CTFrameGetLines(self->frame);
 }
 
+- (void)lineOrigins:(CFRange)range origins:(CGPoint*)origins
+{
+	CTFrameGetLineOrigins(self->frame, range, origins);
+}
+
 @end
 
-struct uiDrawTextLayout {
-	uiprivTextFrame *frame;
-	uiprivTextFrame *forLines;
-	BOOL empty;
-
-	// for converting CFAttributedString indices from/to byte offsets
-	size_t *u8tou16;
-	size_t nUTF8;
-	size_t *u16tou8;
-	size_t nUTF16;
-};
-
 uiDrawTextLayout *uiDrawNewTextLayout(uiDrawTextLayoutParams *p)
 {
 	uiDrawTextLayout *tl;
diff --git a/darwin/future.m b/darwin/future.m
index e6d05ef4..5b64b0a6 100644
--- a/darwin/future.m
+++ b/darwin/future.m
@@ -11,6 +11,8 @@ CFStringRef *uiprivFUTURE_kCTFontOpenTypeFeatureValue = NULL;
 // added in OS X 10.12; we need 10.8
 CFStringRef *uiprivFUTURE_kCTBackgroundColorAttributeName = NULL;
 
+NSOperatingSystemVersion HIGH_SIERRA_VERSION = { .majorVersion = 10, .minorVersion = 13, .patchVersion = 0 };
+
 // note that we treat any error as "the symbols aren't there" (and don't care if dlclose() failed)
 void uiprivLoadFutures(void)
 {
@@ -23,7 +25,9 @@ void uiprivLoadFutures(void)
 #define GET(var, fn) *((void **) (&var)) = dlsym(handle, #fn)
 	GET(uiprivFUTURE_kCTFontOpenTypeFeatureTag, kCTFontOpenTypeFeatureTag);
 	GET(uiprivFUTURE_kCTFontOpenTypeFeatureValue, kCTFontOpenTypeFeatureValue);
-	GET(uiprivFUTURE_kCTBackgroundColorAttributeName, kCTBackgroundColorAttributeName);
+	if (![NSProcessInfo.processInfo isOperatingSystemAtLeastVersion:HIGH_SIERRA_VERSION])
+		GET(uiprivFUTURE_kCTBackgroundColorAttributeName, kCTBackgroundColorAttributeName);
+
 	dlclose(handle);
 }