diff --git a/src/lib/isSlug.js b/src/lib/isSlug.js
index bb1b290bb..da0193137 100644
--- a/src/lib/isSlug.js
+++ b/src/lib/isSlug.js
@@ -1,6 +1,6 @@
 import assertString from './util/assertString';
 
-let charsetRegex = /^[^-_](?!.*?[-_]{2,})([a-z0-9\\-]{1,}).*[^-_]$/;
+let charsetRegex = /^[^\s-_](?!.*?[-_]{2,})([a-z0-9-\\]{1,})[^\s]*[^-_\s]$/;
 
 export default function isSlug(str) {
   assertString(str);
diff --git a/test/validators.js b/test/validators.js
index 0caf824fd..a842e71d9 100755
--- a/test/validators.js
+++ b/test/validators.js
@@ -8369,6 +8369,7 @@ describe('Validators', () => {
         'not-slug-',
         '_not-slug',
         'not-slug_',
+        'not slug',
       ],
     });
   });