diff --git a/bin/prettier.js b/bin/prettier.js
index 02828b83c..983ab2720 100755
--- a/bin/prettier.js
+++ b/bin/prettier.js
@@ -102,32 +102,27 @@ if (argv["find-config-path"] && filepatterns.length) {
 }
 
 function getOptionsForFile(filePath) {
-  const optionsPromise =
-    argv["config"] === false
-      ? Promise.resolve(null)
-      : resolver.resolveConfig(filePath);
+  const options =
+    argv["config"] === false ? null : resolver.resolveConfig.sync(filePath);
 
-  return optionsPromise
-    .then(options => {
-      const parsedArgs = minimist(args, {
-        boolean: booleanOptionNames,
-        string: stringOptionNames,
-        default: Object.assign(
-          {
-            semi: true,
-            "bracket-spacing": true,
-            parser: "babylon"
-          },
-          dashifyObject(options)
-        )
-      });
-
-      return getOptions(Object.assign({}, argv, parsedArgs));
-    })
-    .catch(error => {
-      console.error("Invalid configuration file:", error.toString());
-      process.exit(2);
+  try {
+    const parsedArgs = minimist(args, {
+      boolean: booleanOptionNames,
+      string: stringOptionNames,
+      default: Object.assign(
+        {
+          semi: true,
+          "bracket-spacing": true,
+          parser: "babylon"
+        },
+        dashifyObject(options)
+      )
     });
+    return getOptions(Object.assign({}, argv, parsedArgs));
+  } catch (error) {
+    console.error("Invalid configuration file:", error.toString());
+    process.exit(2);
+  }
 }
 
 function getOptions(argv) {
@@ -324,17 +319,17 @@ if (argv["find-config-path"]) {
   resolveConfig(argv["find-config-path"]);
 } else if (stdin) {
   getStream(process.stdin).then(input => {
-    getOptionsForFile(process.cwd()).then(options => {
-      if (listDifferent(input, options, "(stdin)")) {
-        return;
-      }
+    const options = getOptionsForFile(process.cwd());
 
-      try {
-        writeOutput(format(input, options), options);
-      } catch (e) {
-        handleError("stdin", e);
-      }
-    });
+    if (listDifferent(input, options, "(stdin)")) {
+      return;
+    }
+
+    try {
+      writeOutput(format(input, options), options);
+    } catch (e) {
+      handleError("stdin", e);
+    }
   });
 } else {
   eachFilename(filepatterns, (filename, options) => {
@@ -433,13 +428,12 @@ function listDifferent(input, options, filename) {
 }
 
 function resolveConfig(filePath) {
-  resolver.resolveConfigFile(filePath).then(configFile => {
-    if (configFile) {
-      console.log(path.relative(process.cwd(), configFile));
-    } else {
-      process.exitCode = 1;
-    }
-  });
+  const configFile = resolver.resolveConfigFile.sync(filePath);
+  if (configFile) {
+    console.log(path.relative(process.cwd(), configFile));
+  } else {
+    process.exitCode = 1;
+  }
 }
 
 function writeOutput(result, options) {
@@ -481,12 +475,9 @@ function eachFilename(patterns, callback) {
         process.exitCode = 2;
         return;
       }
-      // Use map series to ensure idempotency
-      mapSeries(ignorer.filter(filePaths), filePath => {
-        return getOptionsForFile(filePath).then(options =>
-          callback(filePath, options)
-        );
-      });
+      ignorer
+        .filter(filePaths)
+        .forEach(filePath => callback(filePath, getOptionsForFile(filePath)));
     })
     .catch(err => {
       console.error(
@@ -496,16 +487,3 @@ function eachFilename(patterns, callback) {
       process.exitCode = 2;
     });
 }
-
-function mapSeries(array, iteratee) {
-  let current = Promise.resolve();
-
-  const promises = array.map((item, i) => {
-    current = current.then(() => {
-      return iteratee(item, i, array);
-    });
-    return current;
-  });
-
-  return Promise.all(promises);
-}