diff --git a/packages/gatsby-source-filesystem/src/__tests__/file-finder.js b/packages/gatsby-source-filesystem/src/__tests__/find-files.js
similarity index 77%
rename from packages/gatsby-source-filesystem/src/__tests__/file-finder.js
rename to packages/gatsby-source-filesystem/src/__tests__/find-files.js
index d9891a993e427..0fb29521c5fd1 100644
--- a/packages/gatsby-source-filesystem/src/__tests__/file-finder.js
+++ b/packages/gatsby-source-filesystem/src/__tests__/find-files.js
@@ -1,10 +1,18 @@
-const fileFinder = require(`../file-finder`)
+const findFiles = require(`../find-files`)
 const path = require(`path`)
 
-describe(`file-finder`, () => {
+describe(`findOnce`, () => {
   it(`resolves an array of file paths`, async done => {
     expect.assertions(3)
-    const queue = await fileFinder(`${__dirname}/fixtures/test-fs`)
+    const queue = await findFiles(`${__dirname}/fixtures/test-fs`, {
+      watch: false,
+      ignored: [
+        `.toBeIgnored.md`,
+        `**/.DS_Store`,
+        `**/.placeholder.md`,
+        `**/notInTheFixture.bar`,
+      ],
+    })
     const expectedQueue = [
       path.join(__dirname, `fixtures`, `test-fs`, `index.md`),
       path.join(__dirname, `fixtures`, `test-fs`, `dirA`, `index.md`),
diff --git a/packages/gatsby-source-filesystem/src/file-finder.js b/packages/gatsby-source-filesystem/src/file-finder.js
deleted file mode 100644
index 6750c4882d81c..0000000000000
--- a/packages/gatsby-source-filesystem/src/file-finder.js
+++ /dev/null
@@ -1,34 +0,0 @@
-const readdirp = require(`readdirp`)
-
-const ignoredRE = /^\./
-const ignored = [`yarn.lock`, `package-lock.json`, `node_modules`, `dist`]
-
-function fileFinder(dir) {
-  return new Promise(resolve => {
-    let fileList = []
-    const stream = readdirp({ root: dir })
-
-    stream.on(`data`, data => {
-      const { name, fullPath, stat } = data
-
-      if (
-        stat.isDirectory() ||
-        ignoredRE.test(name) ||
-        ignored.includes(name)
-      ) {
-        return
-      }
-      if (fullPath.includes(`node_modules`) || fullPath.includes(`build`)) {
-        return
-      }
-      fileList.push(fullPath)
-      return
-    })
-
-    stream.on(`end`, () => {
-      resolve(fileList)
-    })
-  })
-}
-
-module.exports = fileFinder
diff --git a/packages/gatsby-source-filesystem/src/file-watcher.js b/packages/gatsby-source-filesystem/src/file-watcher.js
index f83e69b1277da..a6b9fed4b7fe4 100644
--- a/packages/gatsby-source-filesystem/src/file-watcher.js
+++ b/packages/gatsby-source-filesystem/src/file-watcher.js
@@ -1,6 +1,6 @@
 const path = require(`path`)
-const chokidar = require(`chokidar`)
 const { Machine } = require(`xstate`)
+const findFiles = require(`./find-files`)
 const { createFileNode } = require(`./create-file-node`)
 
 /**
@@ -60,7 +60,8 @@ function fileWatcher(
     )
   })
 
-  const watcher = chokidar.watch(pluginOptions.path, {
+  const watcher = findFiles(pluginOptions.path, {
+    watch: process.env.GATSBY_EXECUTING_COMMAND === `develop`,
     ignored: [
       `**/*.un~`,
       `**/.DS_Store`,
diff --git a/packages/gatsby-source-filesystem/src/find-files.js b/packages/gatsby-source-filesystem/src/find-files.js
new file mode 100644
index 0000000000000..c9034741e4fd3
--- /dev/null
+++ b/packages/gatsby-source-filesystem/src/find-files.js
@@ -0,0 +1,31 @@
+const chokidar = require(`chokidar`)
+const readdirp = require(`readdirp`)
+const anymatch = require(`anymatch`)
+
+const findOnce = (path, options) => {
+  const { ignored } = options
+  return new Promise(resolve => {
+    let fileList = []
+    const stream = readdirp({ root: path })
+
+    stream.on(`data`, data => {
+      if (anymatch(ignored, data.path)) return
+      fileList.push(data.fullPath)
+      return
+    })
+
+    stream.on(`end`, () => {
+      resolve(fileList)
+    })
+  })
+}
+
+module.exports = (path, options) => {
+  const { watch, ignored } = options
+
+  if (watch === true) {
+    return chokidar.watch(path, { ignored })
+  } else {
+    return findOnce(path, { ignored })
+  }
+}