diff --git a/src/alejandra_engine/src/builder.rs b/src/alejandra_engine/src/builder.rs
index 7c6d9bd..2832285 100644
--- a/src/alejandra_engine/src/builder.rs
+++ b/src/alejandra_engine/src/builder.rs
@@ -188,7 +188,7 @@ fn format(
                 rnix::SyntaxKind::NODE_STRING => crate::rules::string::rule,
                 // ${a}
                 rnix::SyntaxKind::NODE_STRING_INTERPOL => {
-                    crate::rules::string_interpol::rule
+                    crate::rules::paren::rule
                 }
                 // !a
                 rnix::SyntaxKind::NODE_UNARY_OP => crate::rules::default,
diff --git a/src/alejandra_engine/src/rules/mod.rs b/src/alejandra_engine/src/rules/mod.rs
index f8ed50a..f28f329 100644
--- a/src/alejandra_engine/src/rules/mod.rs
+++ b/src/alejandra_engine/src/rules/mod.rs
@@ -16,7 +16,6 @@ pub(crate) mod root;
 pub(crate) mod scoped;
 pub(crate) mod select;
 pub(crate) mod string;
-pub(crate) mod string_interpol;
 
 pub(crate) fn default(
     _: &crate::builder::BuildCtx,
diff --git a/src/alejandra_engine/src/rules/string_interpol.rs b/src/alejandra_engine/src/rules/string_interpol.rs
deleted file mode 100644
index ee78fa4..0000000
--- a/src/alejandra_engine/src/rules/string_interpol.rs
+++ /dev/null
@@ -1,60 +0,0 @@
-pub(crate) fn rule(
-    build_ctx: &crate::builder::BuildCtx,
-    node: &rnix::SyntaxNode,
-) -> std::collections::LinkedList<crate::builder::Step> {
-    let mut steps = std::collections::LinkedList::new();
-
-    let mut children = crate::children::Children::new(build_ctx, node);
-
-    let vertical = children.has_comments()
-        || children.has_newlines()
-        || build_ctx.vertical;
-
-    // ${
-    let child = children.get_next().unwrap();
-    steps.push_back(crate::builder::Step::Format(child));
-    if vertical {
-        steps.push_back(crate::builder::Step::Indent);
-        steps.push_back(crate::builder::Step::NewLine);
-        steps.push_back(crate::builder::Step::Pad);
-    }
-
-    // /**/
-    children.drain_trivia(|element| match element {
-        crate::children::Trivia::Comment(text) => {
-            steps.push_back(crate::builder::Step::Comment(text));
-            steps.push_back(crate::builder::Step::NewLine);
-            steps.push_back(crate::builder::Step::Pad);
-        }
-        crate::children::Trivia::Whitespace(_) => {}
-    });
-
-    // expr
-    let child = children.get_next().unwrap();
-    if vertical {
-        steps.push_back(crate::builder::Step::FormatWider(child));
-    } else {
-        steps.push_back(crate::builder::Step::Format(child));
-    }
-
-    // /**/
-    children.drain_trivia(|element| match element {
-        crate::children::Trivia::Comment(text) => {
-            steps.push_back(crate::builder::Step::NewLine);
-            steps.push_back(crate::builder::Step::Pad);
-            steps.push_back(crate::builder::Step::Comment(text));
-        }
-        crate::children::Trivia::Whitespace(_) => {}
-    });
-
-    // }
-    let child = children.get_next().unwrap();
-    if vertical {
-        steps.push_back(crate::builder::Step::Dedent);
-        steps.push_back(crate::builder::Step::NewLine);
-        steps.push_back(crate::builder::Step::Pad);
-    }
-    steps.push_back(crate::builder::Step::Format(child));
-
-    steps
-}
diff --git a/src/alejandra_engine/tests/cases/apply/out b/src/alejandra_engine/tests/cases/apply/out
index 72e7317..99b2c31 100644
--- a/src/alejandra_engine/tests/cases/apply/out
+++ b/src/alejandra_engine/tests/cases/apply/out
@@ -22,8 +22,7 @@
        */
     ))
   ''
-    otherModules=${
-      pkgs.writeText "other-modules.json"
+    otherModules=${pkgs.writeText "other-modules.json"
       (l.toJSON
         (l.mapAttrs
           (pname: subOutputs: let
@@ -32,8 +31,7 @@
               installMethod = "copy";
             });
           in "${pkg}/lib/node_modules/${pname}/node_modules")
-          outputs.subPackages))
-    }
+          outputs.subPackages))}
   ''
   {
     name1 =
diff --git a/src/alejandra_engine/tests/cases/string/out b/src/alejandra_engine/tests/cases/string/out
index 670f6f4..8afc3b8 100644
--- a/src/alejandra_engine/tests/cases/string/out
+++ b/src/alejandra_engine/tests/cases/string/out
@@ -84,12 +84,8 @@
     </plist>''
 
   ''
-    --${
-      "test"
-    }
+    --${"test"}
   ''
 
-  "--${
-    "test"
-  }"
+  "--${"test"}"
 ]