--- OLD/pnm/libpnm3.c	Thu Jan  1 00:00:00 1970
+++ NEW/pnm/libpnm3.c	Thu Jan  1 00:00:00 1970
@@ -65,9 +65,9 @@
 	    {
 	    case PPM_TYPE:
 	    PPM_ASSIGN( bgxel,
-		PPM_GETR(ul) + PPM_GETR(ur) + PPM_GETR(ll) + PPM_GETR(lr) / 4,
-		PPM_GETG(ul) + PPM_GETG(ur) + PPM_GETG(ll) + PPM_GETG(lr) / 4,
-		PPM_GETB(ul) + PPM_GETB(ur) + PPM_GETB(ll) + PPM_GETB(lr) / 4 );
+		(PPM_GETR(ul) + PPM_GETR(ur) + PPM_GETR(ll) + PPM_GETR(lr)) / 4,
+		(PPM_GETG(ul) + PPM_GETG(ur) + PPM_GETG(ll) + PPM_GETG(lr)) / 4,
+		(PPM_GETB(ul) + PPM_GETB(ur) + PPM_GETB(ll) + PPM_GETB(lr)) / 4 );
 	    break;
 
 	    case PGM_TYPE:
@@ -120,8 +120,9 @@
 	switch ( PNM_FORMAT_TYPE(format) )
 	    {
 	    case PPM_TYPE:
-	    PPM_ASSIGN( bgxel, PPM_GETR(l) + PPM_GETR(r) / 2,
-		PPM_GETG(l) + PPM_GETG(r) / 2, PPM_GETB(l) + PPM_GETB(r) / 2 );
+	    PPM_ASSIGN( bgxel, (PPM_GETR(l) + PPM_GETR(r)) / 2,
+		(PPM_GETG(l) + PPM_GETG(r)) / 2,
+		(PPM_GETB(l) + PPM_GETB(r)) / 2 );
 	    break;
 
 	    case PGM_TYPE: