diff --git a/src/pack-individually.ts b/src/pack-individually.ts
index dee79780..2ed7df8f 100644
--- a/src/pack-individually.ts
+++ b/src/pack-individually.ts
@@ -52,8 +52,8 @@ export async function packIndividually() {
   // get a list of external dependencies already listed in package.json
   const externals = Object.keys(require(path.join(buildDir, 'package.json')).dependencies);
 
-  // get a list of all production dependencies
-  const { dependencies } = await packager.getProdDependencies(buildDir, 10);
+  // get a tree of all production dependencies
+  const { dependencies } = await packager.getProdDependencies(buildDir);
 
   // package each function
   await Promise.all(
diff --git a/src/packagers/npm.ts b/src/packagers/npm.ts
index eca0ebbc..27ef1adb 100644
--- a/src/packagers/npm.ts
+++ b/src/packagers/npm.ts
@@ -20,20 +20,20 @@ export class NPM implements Packager {
     return true;
   }
 
-  async getProdDependencies(cwd: string, depth: number) {
+  async getProdDependencies(cwd: string, depth?: number) {
     // Get first level dependency graph
     const command = /^win/.test(process.platform) ? 'npm.cmd' : 'npm';
     const args = [
       'ls',
       '-prod', // Only prod dependencies
       '-json',
-      `-depth=${depth || 1}`
-    ];
+      depth ? `-depth=${depth}` : null,
+    ].filter(Boolean);
 
     const ignoredNpmErrors = [
       { npmError: 'extraneous', log: false },
       { npmError: 'missing', log: false },
-      { npmError: 'peer dep missing', log: true }
+      { npmError: 'peer dep missing', log: true },
     ];
 
     try {
@@ -45,15 +45,22 @@ export class NPM implements Packager {
       if (err instanceof SpawnError) {
         // Only exit with an error if we have critical npm errors for 2nd level inside
         const errors = split('\n', err.stderr);
-        const failed = reduce((f, error) => {
-          if (f) {
-            return true;
-          }
-          return (
-            !isEmpty(error) &&
-            !any(ignoredError => startsWith(`npm ERR! ${ignoredError.npmError}`, error), ignoredNpmErrors)
-          );
-        }, false, errors);
+        const failed = reduce(
+          (f, error) => {
+            if (f) {
+              return true;
+            }
+            return (
+              !isEmpty(error) &&
+              !any(
+                ignoredError => startsWith(`npm ERR! ${ignoredError.npmError}`, error),
+                ignoredNpmErrors
+              )
+            );
+          },
+          false,
+          errors
+        );
 
         if (!failed && !isEmpty(err.stdout)) {
           return { stdout: err.stdout };
@@ -111,10 +118,12 @@ export class NPM implements Packager {
   async runScripts(cwd, scriptNames) {
     const command = /^win/.test(process.platform) ? 'npm.cmd' : 'npm';
 
-    await Promise.all(scriptNames.map(scriptName => {
-      const args = ['run', scriptName];
+    await Promise.all(
+      scriptNames.map(scriptName => {
+        const args = ['run', scriptName];
 
-      return spawnProcess(command, args, { cwd });
-    }));
+        return spawnProcess(command, args, { cwd });
+      })
+    );
   }
 }
diff --git a/src/packagers/packager.ts b/src/packagers/packager.ts
index dcca25b7..b4b8a469 100644
--- a/src/packagers/packager.ts
+++ b/src/packagers/packager.ts
@@ -4,7 +4,7 @@ export interface Packager {
   lockfileName: string;
   copyPackageSectionNames: Array<string>;
   mustCopyModules: boolean;
-  getProdDependencies(cwd: string, depth: number): Promise<JSONObject>;
+  getProdDependencies(cwd: string, depth?: number): Promise<JSONObject>;
   rebaseLockfile(pathToPackageRoot: string, lockfile: JSONObject): JSONObject;
   install(cwd: string): Promise<void>;
   prune(cwd: string): Promise<void>;
diff --git a/src/packagers/yarn.ts b/src/packagers/yarn.ts
index a85cba14..cb1a66bd 100644
--- a/src/packagers/yarn.ts
+++ b/src/packagers/yarn.ts
@@ -24,9 +24,11 @@ export class Yarn implements Packager {
     return false;
   }
 
-  async getProdDependencies(cwd, depth) {
+  async getProdDependencies(cwd: string, depth?: number) {
     const command = /^win/.test(process.platform) ? 'yarn.cmd' : 'yarn';
-    const args = ['list', `--depth=${depth || 1}`, '--json', '--production'];
+    const args = ['list', depth ? `--depth=${depth}` : null, '--json', '--production'].filter(
+      Boolean
+    );
 
     // If we need to ignore some errors add them here
     const ignoredYarnErrors = [];
@@ -38,15 +40,22 @@ export class Yarn implements Packager {
       if (err instanceof SpawnError) {
         // Only exit with an error if we have critical npm errors for 2nd level inside
         const errors = split('\n', err.stderr);
-        const failed = reduce((f, error) => {
-          if (f) {
-            return true;
-          }
-          return (
-            !isEmpty(error) &&
-            !any(ignoredError => startsWith(`npm ERR! ${ignoredError.npmError}`, error), ignoredYarnErrors)
-          );
-        }, false, errors);
+        const failed = reduce(
+          (f, error) => {
+            if (f) {
+              return true;
+            }
+            return (
+              !isEmpty(error) &&
+              !any(
+                ignoredError => startsWith(`npm ERR! ${ignoredError.npmError}`, error),
+                ignoredYarnErrors
+              )
+            );
+          },
+          false,
+          errors
+        );
 
         if (!failed && !isEmpty(err.stdout)) {
           return { stdout: err.stdout };
@@ -67,7 +76,7 @@ export class Yarn implements Packager {
       }
       __[head(splitModule)] = {
         version: join('@', tail(splitModule)),
-        dependencies: convertTrees(tree.children)
+        dependencies: convertTrees(tree.children),
       };
       return __;
     }, {});
@@ -75,7 +84,7 @@ export class Yarn implements Packager {
     const trees = pathOr([], ['data', 'trees'], parsedTree);
     const result = {
       problems: [],
-      dependencies: convertTrees(trees)
+      dependencies: convertTrees(trees),
     };
     return result;
   }
@@ -89,12 +98,16 @@ export class Yarn implements Packager {
     while ((match = fileVersionMatcher.exec(lockfile)) !== null) {
       replacements.push({
         oldRef: match[1],
-        newRef: replace(/\\/g, '/', `${pathToPackageRoot}/${match[1]}`)
+        newRef: replace(/\\/g, '/', `${pathToPackageRoot}/${match[1]}`),
       });
     }
 
     // Replace all lines in lockfile
-    return reduce((__, replacement) => replace(__, replacement.oldRef, replacement.newRef), lockfile, replacements);
+    return reduce(
+      (__, replacement) => replace(__, replacement.oldRef, replacement.newRef),
+      lockfile,
+      replacements
+    );
   }
 
   async install(cwd) {
@@ -111,6 +124,8 @@ export class Yarn implements Packager {
 
   async runScripts(cwd, scriptNames: string[]) {
     const command = /^win/.test(process.platform) ? 'yarn.cmd' : 'yarn';
-    await Promise.all(scriptNames.map(scriptName => spawnProcess(command, ['run', scriptName], { cwd })));
+    await Promise.all(
+      scriptNames.map(scriptName => spawnProcess(command, ['run', scriptName], { cwd }))
+    );
   }
 }