diff --git a/src/builtin/meta.rs b/src/builtin/meta.rs
index d37cd47..bf7fc02 100644
--- a/src/builtin/meta.rs
+++ b/src/builtin/meta.rs
@@ -188,8 +188,8 @@ fn get_function(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<Value
         },
         parser.global_scope,
     ) {
-        Ok(f) => SassFunction::UserDefined(Box::new(f), name),
-        Err(..) => match GLOBAL_FUNCTIONS.get(name.as_str()) {
+        Some(f) => SassFunction::UserDefined(Box::new(f), name),
+        None => match GLOBAL_FUNCTIONS.get(name.as_str()) {
             Some(f) => SassFunction::Builtin(f.clone(), name),
             None => return Err((format!("Function not found: {}", name), args.span()).into()),
         },
diff --git a/src/parse/value/parse.rs b/src/parse/value/parse.rs
index 51d4cdb..c890ddb 100644
--- a/src/parse/value/parse.rs
+++ b/src/parse/value/parse.rs
@@ -263,8 +263,8 @@ impl<'a> Parser<'a> {
                 },
                 self.global_scope,
             ) {
-                Ok(f) => f,
-                Err(_) => {
+                Some(f) => f,
+                None => {
                     if let Some(f) = GLOBAL_FUNCTIONS.get(as_ident.as_str()) {
                         return Ok(IntermediateValue::Value(HigherIntermediateValue::Function(
                             SassFunction::Builtin(f.clone(), as_ident),
diff --git a/src/scope.rs b/src/scope.rs
index c4f5aef..90e30f7 100644
--- a/src/scope.rs
+++ b/src/scope.rs
@@ -57,11 +57,8 @@ impl Scope {
         self.mixins.contains_key(name)
     }
 
-    fn get_fn(&self, name: Spanned<&Identifier>) -> SassResult<Function> {
-        match self.functions.get(name.node) {
-            Some(v) => Ok(v.clone()),
-            None => Err(("Undefined function.", name.span).into()),
-        }
+    fn get_fn(&self, name: &Identifier) -> Option<Function> {
+        self.functions.get(name).cloned()
     }
 
     pub fn insert_fn<T: Into<Identifier>>(&mut self, s: T, v: Function) -> Option<Function> {
@@ -218,13 +215,13 @@ impl Scopes {
         &'a self,
         name: Spanned<&Identifier>,
         global_scope: &'a Scope,
-    ) -> SassResult<Function> {
+    ) -> Option<Function> {
         for scope in self.0.iter().rev() {
             if scope.fn_exists(&name.node) {
-                return scope.get_fn(name);
+                return scope.get_fn(name.node);
             }
         }
-        global_scope.get_fn(name)
+        global_scope.get_fn(name.node)
     }
 
     pub fn fn_exists(&self, name: &Identifier, global_scope: &Scope) -> bool {