diff --git a/less/forms.less b/less/forms.less
index 6077ae7a3e..aefc0dea5c 100644
--- a/less/forms.less
+++ b/less/forms.less
@@ -325,12 +325,12 @@ input[type="checkbox"] {
 
 .input-sm,
 .form-group-sm .form-control {
-  .input-size(@input-height-small; @padding-small-vertical; @padding-small-horizontal; @font-size-small; @line-height-small; @border-radius-small);
+  .input-size(@input-height-small; @padding-small-vertical; @padding-small-horizontal; @font-size-small; @line-height-small; @input-border-radius-small);
 }
 
 .input-lg,
 .form-group-lg .form-control {
-  .input-size(@input-height-large; @padding-large-vertical; @padding-large-horizontal; @font-size-large; @line-height-large; @border-radius-large);
+  .input-size(@input-height-large; @padding-large-vertical; @padding-large-horizontal; @font-size-large; @line-height-large; @input-border-radius-large);
 }
 
 
diff --git a/less/variables.less b/less/variables.less
index 48b9834561..5fc82df6e9 100644
--- a/less/variables.less
+++ b/less/variables.less
@@ -182,8 +182,15 @@
 @input-color:                    @gray;
 //** `<input>` border color
 @input-border:                   #ccc;
-//** `<input>` border radius
+
+// TODO: Rename `@input-border-radius` to `@input-border-radius-base` in v4
+//** Default `.form-control` border radius
 @input-border-radius:            @border-radius-base;
+//** Large `.form-control` border radius
+@input-border-radius-large:      @border-radius-large;
+//** Small `.form-control` border radius
+@input-border-radius-small:      @border-radius-small;
+
 //** Border color for inputs on focus
 @input-border-focus:             #66afe9;