diff --git a/CHANGELOG.md b/CHANGELOG.md
index d1fce67b5..e2c5767ce 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Ensure CSS variable shorthand uses valid CSS variables ([#15738](https://github.com/tailwindlabs/tailwindcss/pull/15738))
 - Ensure font-size utilities with `none` modifier have a line-height set e.g.: `text-sm/none` ([#15921](https://github.com/tailwindlabs/tailwindcss/pull/15921))
 - Ensure font-size utilities with unknown modifier don't generate CSS ([#15921](https://github.com/tailwindlabs/tailwindcss/pull/15921))
+- _Upgrade_: Ensure JavaScript config files on different drives are correctly migrated ([#15927](https://github.com/tailwindlabs/tailwindcss/pull/15927))
 
 ## [4.0.0] - 2025-01-21
 
diff --git a/packages/@tailwindcss-upgrade/src/migrate.ts b/packages/@tailwindcss-upgrade/src/migrate.ts
index 53b228256..45e758496 100644
--- a/packages/@tailwindcss-upgrade/src/migrate.ts
+++ b/packages/@tailwindcss-upgrade/src/migrate.ts
@@ -435,7 +435,7 @@ export async function linkConfigs(
       // If the path points to a file in the same directory, `path.relative` will
       // remove the leading `./` and we need to add it back in order to still
       // consider the path relative
-      if (!relative.startsWith('.')) {
+      if (!relative.startsWith('.') && !path.isAbsolute(relative)) {
         relative = './' + relative
       }
 
diff --git a/packages/@tailwindcss-upgrade/src/template/prepare-config.ts b/packages/@tailwindcss-upgrade/src/template/prepare-config.ts
index f5a817d40..e936df6a3 100644
--- a/packages/@tailwindcss-upgrade/src/template/prepare-config.ts
+++ b/packages/@tailwindcss-upgrade/src/template/prepare-config.ts
@@ -40,7 +40,7 @@ export async function prepareConfig(
     // If the path points to a file in the same directory, `path.relative` will
     // remove the leading `./` and we need to add it back in order to still
     // consider the path relative
-    if (!relative.startsWith('.')) {
+    if (!relative.startsWith('.') && !path.isAbsolute(relative)) {
       relative = './' + relative
     }
 
@@ -49,7 +49,7 @@ export async function prepareConfig(
     let newPrefix = userConfig.prefix ? migratePrefix(userConfig.prefix) : null
     let input = css`
       @import 'tailwindcss' ${newPrefix ? `prefix(${newPrefix})` : ''};
-      @config './${relative}';
+      @config '${relative}';
     `
 
     let [compiler, designSystem] = await Promise.all([