diff --git a/libm/src/e_atan2.c b/libm/src/e_atan2.c
index 073f81b..56c05a5 100644
--- a/libm/src/e_atan2.c
+++ b/libm/src/e_atan2.c
@@ -68,7 +68,7 @@
 	if(((ix|((lx|-lx)>>31))>0x7ff00000)||
 	   ((iy|((ly|-ly)>>31))>0x7ff00000))	/* x or y is NaN */
 	   return x+y;
-	if((hx-0x3ff00000|lx)==0) return atan(y);   /* x=1.0 */
+	if(((hx-0x3ff00000) | lx)==0) return atan(y);   /* x=1.0 */
 	m = ((hy>>31)&1)|((hx>>30)&2);	/* 2*sign(x)+sign(y) */
 
     /* when y = 0 */