diff --git a/src/parse/value.rs b/src/parse/value.rs
index 5b7ae5d..ed9bf1f 100644
--- a/src/parse/value.rs
+++ b/src/parse/value.rs
@@ -372,8 +372,12 @@ impl<'a> Parser<'a> {
             }
             '&' => {
                 let span = self.toks.next().unwrap().pos();
-                IntermediateValue::Value(self.super_selectors.last().clone().into_value())
-                    .span(span)
+                if self.super_selectors.is_empty() {
+                    IntermediateValue::Value(Value::Null).span(span)
+                } else {
+                    IntermediateValue::Value(self.super_selectors.last().clone().into_value())
+                        .span(span)
+                }
             }
             '#' => {
                 if let Some(Token { kind: '{', pos }) = self.toks.peek_forward(1) {
diff --git a/tests/selectors.rs b/tests/selectors.rs
index 2e8731d..a9412c8 100644
--- a/tests/selectors.rs
+++ b/tests/selectors.rs
@@ -653,6 +653,11 @@ test!(
     ":nth-child(ODD) {\n  color: &;\n}\n",
     ":nth-child(odd) {\n  color: :nth-child(odd);\n}\n"
 );
+test!(
+    super_selector_is_null_when_at_root,
+    "@mixin foo {\n    #{if(&, 'true', 'false')} {\n        color: red;\n    }\n}\n\n@include foo;\n\na {\n    @include foo;\n}\n",
+    "false {\n  color: red;\n}\n\na true {\n  color: red;\n}\n"
+);
 error!(
     a_n_plus_b_n_invalid_odd,
     ":nth-child(ofdd) {\n  color: &;\n}\n", "Error: Expected \"odd\"."