diff --git a/sys/include/memdraw.h b/sys/include/memdraw.h
index 6e527696a..997cbbea5 100644
--- a/sys/include/memdraw.h
+++ b/sys/include/memdraw.h
@@ -149,7 +149,7 @@ extern void	memarc(Memimage*, Point, int, int, int, Memimage*, Point, int, int,
 extern Rectangle	memlinebbox(Point, Point, int, int, int);
 extern int	memlineendsize(int);
 extern void	_memmkcmap(void);
-extern void	memimageinit(void);
+extern int	memimageinit(void);
 
 /*
  * Subfont management
diff --git a/sys/man/2/memdraw b/sys/man/2/memdraw
index ac1b73961..df68b699d 100644
--- a/sys/man/2/memdraw
+++ b/sys/man/2/memdraw
@@ -94,7 +94,7 @@ int	drawdebug;
 .PP
 .ft L
 .nf
-void	memimageinit(void)
+int	memimageinit(void)
 ulong*	wordaddr(Memimage *i, Point p)
 uchar*	byteaddr(Memimage *i, Point p)
 void	memimagemove(void *from, void *to)
@@ -213,7 +213,8 @@ as well as the replicated solid color images
 and
 .BR memwhite .
 It should be called before referring to any of these images
-and before calling any of the other library functions.
+and before calling any of the other library functions. It
+returns non-zero on error.
 .PP
 Each 
 .B Memimage
diff --git a/sys/src/libmemdraw/alloc.c b/sys/src/libmemdraw/alloc.c
index d2852c3c4..aa3597f71 100644
--- a/sys/src/libmemdraw/alloc.c
+++ b/sys/src/libmemdraw/alloc.c
@@ -121,7 +121,7 @@ freememimage(Memimage *i)
 {
 	if(i == nil)
 		return;
-	if(i->data->ref-- == 1 && i->data->allocd){
+	if(--i->data->ref == 0 && i->data->allocd){
 		if(i->data->base)
 			poolfree(imagmem, i->data->base);
 		free(i->data);
diff --git a/sys/src/libmemdraw/draw.c b/sys/src/libmemdraw/draw.c
index 5a15e4dae..96cb01e44 100644
--- a/sys/src/libmemdraw/draw.c
+++ b/sys/src/libmemdraw/draw.c
@@ -6,7 +6,6 @@
 
 extern Pool* imagmem;
 int drawdebug;
-static int	tablesbuilt;
 
 /* perfect approximation to NTSC = .299r+.587g+.114b when 0 ≤ r,g,b < 256 */
 #define RGB2K(r,g,b)	((156763*(r)+307758*(g)+59769*(b))>>19)
@@ -54,16 +53,15 @@ Memimage *memopaque;
 
 int	_ifmt(Fmt*);
 
-void
+int
 memimageinit(void)
 {
 	static int didinit = 0;
 
 	if(didinit)
-		return;
-
-	didinit = 1;
+		return 0;
 
+	if(imagmem != nil)
 	if(strcmp(imagmem->name, "Image") == 0 || strcmp(imagmem->name, "image") == 0)
 		imagmem->move = memimagemove;
 
@@ -75,22 +73,25 @@ memimageinit(void)
 	fmtinstall('b', _ifmt);
 
 	memones = allocmemimage(Rect(0,0,1,1), GREY1);
+	memzeros = allocmemimage(Rect(0,0,1,1), GREY1);
+	if(memones == nil || memzeros == nil)
+		return -1;
+
 	memones->flags |= Frepl;
 	memones->clipr = Rect(-0x3FFFFFF, -0x3FFFFFF, 0x3FFFFFF, 0x3FFFFFF);
 	*byteaddr(memones, ZP) = ~0;
 
-	memzeros = allocmemimage(Rect(0,0,1,1), GREY1);
 	memzeros->flags |= Frepl;
 	memzeros->clipr = Rect(-0x3FFFFFF, -0x3FFFFFF, 0x3FFFFFF, 0x3FFFFFF);
 	*byteaddr(memzeros, ZP) = 0;
 
-	if(memones == nil || memzeros == nil)
-		assert(0 /*cannot initialize memimage library */);	/* RSC BUG */
-
 	memwhite = memones;
 	memblack = memzeros;
 	memopaque = memones;
 	memtransparent = memzeros;
+
+	didinit = 1;
+	return 0;
 }
 
 static ulong imgtorgba(Memimage*, ulong);
@@ -354,13 +355,6 @@ mktables(void)
 {
 	int i, j, mask, sh, small;
 		
-	if(tablesbuilt)
-		return;
-
-	fmtinstall('R', Rfmt);
-	fmtinstall('P', Pfmt);
-	tablesbuilt = 1;
-
 	/* bit replication up to 8 bits */
 	for(i=0; i<256; i++){
 		for(j=0; j<=8; j++){	/* j <= 8 [sic] */
diff --git a/sys/src/libmemdraw/fillpoly.c b/sys/src/libmemdraw/fillpoly.c
index 6d5370a9a..6ecccc0a1 100644
--- a/sys/src/libmemdraw/fillpoly.c
+++ b/sys/src/libmemdraw/fillpoly.c
@@ -79,7 +79,7 @@ _memfillpolysc(Memimage *dst, Point *vert, int nvert, int w, Memimage *src, Poin
 	Point p0;
 	int i;
 
-	if(nvert == 0)
+	if(nvert <= 0)
 		return;
 
 	seg = malloc((nvert+2)*sizeof(Seg*));