diff --git a/src/builtin/meta.rs b/src/builtin/meta.rs
index 6e72e21..e2a3c0c 100644
--- a/src/builtin/meta.rs
+++ b/src/builtin/meta.rs
@@ -127,7 +127,7 @@ fn mixin_exists(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<Value
     args.max_args(2)?;
     match parser.arg(&mut args, 0, "name")? {
         Value::String(s, _) => Ok(Value::bool(
-            parser.scopes.last().mixin_exists(&s, parser.global_scope),
+            parser.scopes.last().mixin_exists(s, parser.global_scope),
         )),
         v => Err((
             format!("$name: {} is not a string.", v.inspect(args.span())?),
@@ -141,7 +141,7 @@ fn function_exists(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<Va
     args.max_args(2)?;
     match parser.arg(&mut args, 0, "name")? {
         Value::String(s, _) => Ok(Value::bool(
-            parser.scopes.last().fn_exists(&s, parser.global_scope),
+            parser.scopes.last().fn_exists(s, parser.global_scope),
         )),
         v => Err((
             format!("$name: {} is not a string.", v.inspect(args.span())?),
diff --git a/src/common.rs b/src/common.rs
index 4f9ce1e..882793c 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -115,7 +115,11 @@ pub(crate) struct Identifier(String);
 
 impl From<String> for Identifier {
     fn from(s: String) -> Identifier {
-        Identifier(s.replace('_', "-"))
+        if s.contains('_') {
+            Identifier(s.replace('_', "-"))
+        } else {
+            Identifier(s)
+        }
     }
 }
 
diff --git a/src/parse/args.rs b/src/parse/args.rs
index 0e7dbc8..f272ea7 100644
--- a/src/parse/args.rs
+++ b/src/parse/args.rs
@@ -176,7 +176,7 @@ impl<'a> Parser<'a> {
                             if name.is_empty() {
                                 CallArg::Positional(args.len())
                             } else {
-                                CallArg::Named(name.into())
+                                CallArg::Named(mem::take(&mut name).into())
                             },
                             self.parse_value_from_vec(val),
                         );
@@ -261,7 +261,7 @@ impl<'a> Parser<'a> {
                     if name.is_empty() {
                         CallArg::Positional(args.len())
                     } else {
-                        CallArg::Named(name.as_str().into())
+                        CallArg::Named(mem::take(&mut name).into())
                     },
                     self.parse_value_from_vec(mem::take(&mut val)),
                 );