diff --git a/packages/gatsby-plugin-sharp/src/__tests__/index.js b/packages/gatsby-plugin-sharp/src/__tests__/index.js
index 9d4800e5879bf..ac0af9d4c42e4 100644
--- a/packages/gatsby-plugin-sharp/src/__tests__/index.js
+++ b/packages/gatsby-plugin-sharp/src/__tests__/index.js
@@ -1,6 +1,6 @@
 const path = require(`path`)
 
-const { base64, responsiveSizes } = require(`../`)
+const { base64, responsiveSizes, resolutions } = require(`../`)
 
 describe(`gatsby-plugin-sharp`, () => {
   const args = {
@@ -73,6 +73,42 @@ describe(`gatsby-plugin-sharp`, () => {
     })
   })
 
+  describe(`resolutions`, () => {
+    console.warn = jest.fn()
+
+    beforeEach(() => {
+      console.warn.mockClear()
+    })
+
+    afterAll(() => {
+      console.warn.mockClear()
+    })
+
+    it(`does not warn when the requested width is equal to the image width`, async () => {
+      const args = { width: 1 }
+
+      const result = await resolutions({
+        file,
+        args,
+      })
+
+      expect(result.width).toEqual(1)
+      expect(console.warn).toHaveBeenCalledTimes(0)
+    })
+
+    it(`warns when the requested width is greater than the image width`, async () => {
+      const args = { width: 2 }
+
+      const result = await resolutions({
+        file,
+        args,
+      })
+
+      expect(result.width).toEqual(1)
+      expect(console.warn).toHaveBeenCalledTimes(1)
+    })
+  })
+
   describe(`base64`, () => {
     it(`converts image to base64`, async () => {
       const result = await base64({
diff --git a/packages/gatsby-plugin-sharp/src/index.js b/packages/gatsby-plugin-sharp/src/index.js
index ebe27c7bef9a8..953e3cda8abdb 100644
--- a/packages/gatsby-plugin-sharp/src/index.js
+++ b/packages/gatsby-plugin-sharp/src/index.js
@@ -517,7 +517,7 @@ async function resolutions({ file, args = {} }) {
   sizes.push(options.width * 3)
   const dimensions = imageSize(file.absolutePath)
 
-  const filteredSizes = sizes.filter(size => size < dimensions.width)
+  const filteredSizes = sizes.filter(size => size <= dimensions.width)
 
   // If there's no sizes after filtering (e.g. image is smaller than what's
   // requested, add back the original so there's at least something)