diff --git a/scss/_custom-forms.scss b/scss/_custom-forms.scss
index 48f292bdfb..8b3a74bc0b 100644
--- a/scss/_custom-forms.scss
+++ b/scss/_custom-forms.scss
@@ -268,6 +268,12 @@
   &::-ms-expand {
     display: none;
   }
+
+  // Remove outline from select box in FF
+  &:-moz-focusring {
+    color: transparent;
+    text-shadow: 0 0 0 $custom-select-color;
+  }
 }
 
 .custom-select-sm {
diff --git a/scss/_forms.scss b/scss/_forms.scss
index a290270d74..7a9a653e45 100644
--- a/scss/_forms.scss
+++ b/scss/_forms.scss
@@ -30,6 +30,12 @@
     border: 0;
   }
 
+  // Remove select outline from select box in FF
+  &:-moz-focusring {
+    color: transparent;
+    text-shadow: 0 0 0 $input-color;
+  }
+
   // Customize the `:focus` state to imitate native WebKit styles.
   @include form-control-focus($ignore-warning: true);