diff --git a/migration-guide.md b/migration-guide.md
index d86649f..1339b97 100644
--- a/migration-guide.md
+++ b/migration-guide.md
@@ -2,6 +2,36 @@
 
 ## 🚨 Breaking Changes
 
+### Breakpoint Boundaries
+
+Prior to `v4.0.0` `twrnc` displayed subtly different behavior for media query ranges from
+TailwindCSS. Specifically, TailwindCSS media queries are **inclusive** of the _minimum_,
+and older versions of `twrnc` were **exclusive** of the range minimum. In practical terms
+that means that a utility like `md:bg-black` is applicable in TailwindCSS _when the screen
+size is **exactly** `768px` wide,_ whereas in `twrnc@3.x.x` that class would only begin to
+apply at **`769px`.** Version `4.0.0` corrects this off-by-one error, making the library
+more consistent with TailwindCSS.
+
+We think that this will not affect most library consumers, but it is possible that you
+could see a difference in appearance if your device window size is precisely the same as a
+media query range minimum, so this is technically a breaking change.
+
+If you'd like to restore the prior behavior, you can customize your theme's `screens`,
+settings:
+
+```js
+module.exports = {
+  theme: {
+    screens: {
+      sm: '641px',
+      md: '769px',
+      lg: '1025px',
+      xl: '1281px',
+    },
+  },
+};
+```
+
 ### `useAppColorScheme()` Initialization
 
 _NB: If you were not using dark mode, or were only observing the device's color scheme
diff --git a/src/ClassParser.ts b/src/ClassParser.ts
index f7cafd6..7dfd081 100644
--- a/src/ClassParser.ts
+++ b/src/ClassParser.ts
@@ -63,7 +63,7 @@ export default class ClassParser {
         const windowWidth = device.windowDimensions?.width;
         if (windowWidth) {
           const [min, max] = widthBreakpoints[prefix] ?? [0, 0];
-          if (windowWidth <= min || windowWidth > max) {
+          if (windowWidth < min || windowWidth >= max) {
             // breakpoint does not match
             this.isNull = true;
           }
diff --git a/src/__tests__/screens.spec.ts b/src/__tests__/screens.spec.ts
index 282ba05..16c4b43 100644
--- a/src/__tests__/screens.spec.ts
+++ b/src/__tests__/screens.spec.ts
@@ -54,7 +54,6 @@ describe(`screens()`, () => {
   ];
 
   // https://tailwindcss.com/docs/breakpoints#custom-media-queries
-
   test.each(cases)(`converts tw screens to ranges`, (input, expected) => {
     expect(screens(input)).toEqual(expected);
   });
diff --git a/src/__tests__/tw.spec.ts b/src/__tests__/tw.spec.ts
index c9c8162..13cef8e 100644
--- a/src/__tests__/tw.spec.ts
+++ b/src/__tests__/tw.spec.ts
@@ -30,6 +30,37 @@ describe(`tw`, () => {
     expect(tw`md:text-lg text-xs`).toMatchObject({ fontSize: 18 });
   });
 
+  test(`media queries boundaries`, () => {
+    tw = create();
+    // default breakpoints
+    const utilities = `text-xs sm:text-lg md:text-xl lg:text-2xl xl:text-3xl`;
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 12 });
+    tw.setWindowDimensions({ width: 500, height: 500 });
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 12 });
+    tw.setWindowDimensions({ width: 639, height: 500 });
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 12 });
+    tw.setWindowDimensions({ width: 640, height: 500 });
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 18 });
+    tw.setWindowDimensions({ width: 767, height: 500 });
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 18 });
+    tw.setWindowDimensions({ width: 768, height: 500 });
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 20 });
+    tw.setWindowDimensions({ width: 1023, height: 500 });
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 20 });
+    tw.setWindowDimensions({ width: 1024, height: 500 });
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 24 });
+    tw.setWindowDimensions({ width: 1279, height: 500 });
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 24 });
+    tw.setWindowDimensions({ width: 1280, height: 500 });
+    expect(tw.style(utilities)).toMatchObject({ fontSize: 30 });
+    // custom breakpoints
+    tw = create({ theme: { screens: { custom: `555px` } } });
+    tw.setWindowDimensions({ width: 554, height: 500 });
+    expect(tw`text-xs custom:text-lg`).toMatchObject({ fontSize: 12 });
+    tw.setWindowDimensions({ width: 555, height: 500 });
+    expect(tw`text-xs custom:text-lg`).toMatchObject({ fontSize: 18 });
+  });
+
   test(`multiple media queries`, () => {
     const config: TwConfig = { theme: { screens: { sm: `640px`, md: `768px` } } };
     tw = create(config);
diff --git a/src/create.ts b/src/create.ts
index 6e1aa56..5129ecb 100644
--- a/src/create.ts
+++ b/src/create.ts
@@ -65,11 +65,6 @@ export function create(customConfig: TwConfig, platform: Platform): TailwindFn {
   tailwindFn.memoBuster = ``;
   configureCache();
 
-  // get back to cjs
-  // probably need to implement the check for if isset
-  //   in order to not be a breaking change
-  // also, in this branch, add _unstableUpdateContext func
-
   function configureCache(): void {
     const cacheGroup = deriveCacheGroup();
     tailwindFn.memoBuster = `twrnc-memobuster-key--${cacheGroup}`;