diff --git a/src/printer.js b/src/printer.js
index 991c1862b..bc31fab36 100644
--- a/src/printer.js
+++ b/src/printer.js
@@ -1437,21 +1437,6 @@ function genericPrintNoParens(path, options, print, args) {
     case "TemplateLiteral":
       var expressions = path.map(print, "expressions");
 
-      function removeLines(doc) {
-        // Force this doc into flat mode by statically converting all
-        // lines into spaces (or soft lines into nothing). Hard lines
-        // should still output because there's too great of a chance
-        // of breaking existing assumptions otherwise.
-        return docUtils.mapDoc(doc, d => {
-          if (d.type === "line" && !d.hard) {
-            return d.soft ? "" : " ";
-          } else if (d.type === "if-break") {
-            return d.flatContents || "";
-          }
-          return d;
-        });
-      }
-
       parts.push("`");
 
       path.each(function(childPath) {
@@ -2291,7 +2276,7 @@ function printFunctionParams(path, print, options, expandArg) {
   //   })                    ) => {
   //                         })
   if (expandArg) {
-    return group(concat(["(", join(", ", printed), ")"]));
+    return group(concat(["(", join(", ", printed.map(removeLines)), ")"]));
   }
 
   // Single object destructuring should hug
@@ -3579,6 +3564,21 @@ function printArrayItems(path, options, printPath, print) {
   return concat(printedElements);
 }
 
+function removeLines(doc) {
+  // Force this doc into flat mode by statically converting all
+  // lines into spaces (or soft lines into nothing). Hard lines
+  // should still output because there's too great of a chance
+  // of breaking existing assumptions otherwise.
+  return docUtils.mapDoc(doc, d => {
+    if (d.type === "line" && !d.hard) {
+      return d.soft ? "" : " ";
+    } else if (d.type === "if-break") {
+      return d.flatContents || "";
+    }
+    return d;
+  });
+}
+
 function printAstToDoc(ast, options) {
   function printGenerically(path, args) {
     return comments.printComments(
diff --git a/tests/last_argument_expansion/__snapshots__/jsfmt.spec.js.snap b/tests/last_argument_expansion/__snapshots__/jsfmt.spec.js.snap
index 96e5329a0..d56fb1305 100644
--- a/tests/last_argument_expansion/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/last_argument_expansion/__snapshots__/jsfmt.spec.js.snap
@@ -39,6 +39,37 @@ export default function searchUsers(action$) {
 
 `;
 
+exports[`break.js 1`] = `
+export default class AddAssetHtmlPlugin {
+  apply(compiler: WebpackCompilerType) {
+    compiler.plugin('compilation', (compilation: WebpackCompilationType) => {
+      compilation.plugin('html-webpack-plugin-before-html', (callback: Callback<any>) => {
+        addAllAssetsToCompilation(this.assets, compilation, htmlPluginData, callback);
+      });
+    });
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+export default class AddAssetHtmlPlugin {
+  apply(compiler: WebpackCompilerType) {
+    compiler.plugin("compilation", (compilation: WebpackCompilationType) => {
+      compilation.plugin(
+        "html-webpack-plugin-before-html",
+        (callback: Callback<any>) => {
+          addAllAssetsToCompilation(
+            this.assets,
+            compilation,
+            htmlPluginData,
+            callback
+          );
+        }
+      );
+    });
+  }
+}
+
+`;
+
 exports[`break-parent.js 1`] = `
 ({
   processors: [
diff --git a/tests/last_argument_expansion/break.js b/tests/last_argument_expansion/break.js
new file mode 100644
index 000000000..cc736b0c3
--- /dev/null
+++ b/tests/last_argument_expansion/break.js
@@ -0,0 +1,9 @@
+export default class AddAssetHtmlPlugin {
+  apply(compiler: WebpackCompilerType) {
+    compiler.plugin('compilation', (compilation: WebpackCompilationType) => {
+      compilation.plugin('html-webpack-plugin-before-html', (callback: Callback<any>) => {
+        addAllAssetsToCompilation(this.assets, compilation, htmlPluginData, callback);
+      });
+    });
+  }
+}