diff --git a/lib/node_modules/@stdlib/math/base/special/cosd/lib/main.js b/lib/node_modules/@stdlib/math/base/special/cosd/lib/main.js
index e8e5718878b6..48d2d6de60e1 100644
--- a/lib/node_modules/@stdlib/math/base/special/cosd/lib/main.js
+++ b/lib/node_modules/@stdlib/math/base/special/cosd/lib/main.js
@@ -52,7 +52,7 @@ var isInteger = require( '@stdlib/math/base/assert/is-integer' );
 function cosd( x ) {
 	var xRad;
 
-	if (isInteger(((x / 90) + 1) / 2) || Infinity < x || -Infinity > x) {
+	if (isInteger(((x / 90) - 1) / 2) || Infinity < x || -Infinity > x) {
 		return 0;
 	}