diff --git a/src/args.rs b/src/args.rs
index 41e519b..ef010a4 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -172,7 +172,7 @@ pub(crate) fn eat_call_args<I: Iterator<Item = Token>>(
             match tok.kind {
                 ')' => {
                     args.insert(
-                        name,
+                        name.replace('_', "-"),
                         Value::from_tokens(&mut val.into_iter().peekable(), scope, super_selector)?,
                     );
                     return Ok(CallArgs(args));
@@ -191,7 +191,7 @@ pub(crate) fn eat_call_args<I: Iterator<Item = Token>>(
         }
 
         args.insert(
-            name,
+            name.replace('_', "-"),
             Value::from_tokens(
                 &mut val.clone().into_iter().peekable(),
                 scope,
diff --git a/tests/mixins.rs b/tests/mixins.rs
index acd9ca2..6c3865d 100644
--- a/tests/mixins.rs
+++ b/tests/mixins.rs
@@ -189,3 +189,8 @@ test!(
     "@mixin foo {\n  color: red\n}\n\na {\n  @include foo;\n}\n",
     "a {\n  color: red;\n}\n"
 );
+test!(
+    args_interchangable_hypen_underscore,
+    "@mixin foo($a-b) {\n  color: $a-b;\n  color: $a_b;\n}\na {\n  @include foo($a_b: a);\n  @include foo($a-b: a);\n}\n",
+    "a {\n  color: a;\n  color: a;\n  color: a;\n  color: a;\n}\n"
+);