diff --git a/integrations/vite/build-watch.test.ts b/integrations/vite/build-watch.test.ts
index a1f6af970..10008f4b8 100644
--- a/integrations/vite/build-watch.test.ts
+++ b/integrations/vite/build-watch.test.ts
@@ -1,5 +1,5 @@
 import path from 'node:path'
-import { candidate, css, js, json, test } from '../utils'
+import { candidate, css, html, js, json, test } from '../utils'
 
 test(
   'build watch ignores a custom output directory',
@@ -47,8 +47,12 @@ test(
 
         document.body.innerHTML = '<div class="underline">Hello</div>'
       `,
-      'resources/css/app.css': css` @import 'tailwindcss'; `,
+      'resources/css/app.css': css`
+        @import 'tailwindcss';
+        @source '../../assets/source.html';
+      `,
       'assets/app.js': js` console.log('previous build') `,
+      'assets/source.html': html` <div class="font-black"></div> `,
       'assets/styles.css': css`
         .previous-build {
           display: block;
@@ -64,7 +68,7 @@ test(
     await process.onStdout((message) => message.includes('built in'))
 
     let output = path.join(root, 'assets/styles.css')
-    await fs.expectFileToContain(output, candidate`underline`)
+    await fs.expectFileToContain(output, [candidate`font-black`, candidate`underline`])
 
     process.flush()
     let result = await Promise.race([
diff --git a/packages/@tailwindcss-vite/src/index.ts b/packages/@tailwindcss-vite/src/index.ts
index c9b67d627..e84946978 100644
--- a/packages/@tailwindcss-vite/src/index.ts
+++ b/packages/@tailwindcss-vite/src/index.ts
@@ -339,6 +339,10 @@ class Root {
   // The lazily-initialized Tailwind scanner.
   private scanner?: Scanner
 
+  // A scanner for explicit `@source` paths that can opt back into paths which
+  // are excluded from automatic source detection.
+  private explicitScanner?: Scanner
+
   // List of all candidates that were being returned by the root scanner during
   // the lifetime of the root.
   private candidates: Set<string> = new Set<string>()
@@ -433,7 +437,7 @@ class Root {
         return [{ ...this.compiler.root, negated: false }]
       })().concat(this.compiler.sources)
 
-      if (this.buildOutputDirectory !== null) {
+      if (this.buildOutputDirectory !== null && this.compiler.root === null) {
         // Watching files emitted by Vite would trigger another build every time
         // the output is written.
         sources.push({
@@ -444,6 +448,10 @@ class Root {
       }
 
       this.scanner = new Scanner({ sources })
+      this.explicitScanner =
+        this.compiler.sources.length > 0
+          ? new Scanner({ sources: this.compiler.sources })
+          : undefined
       DEBUG && I.end('Setup scanner')
     } else {
       for (let buildDependency of this.buildDependencies.keys()) {
@@ -469,47 +477,55 @@ class Root {
       // setup a new scanner and compiler every time we request the CSS file
       // (regardless whether it actually changed or not).
       DEBUG && I.start('Scan for candidates')
-      for (let candidate of this.scanner.scan()) {
-        this.candidates.add(candidate)
+      for (let scanner of [this.scanner, this.explicitScanner]) {
+        if (!scanner) continue
+
+        for (let candidate of scanner.scan()) {
+          this.candidates.add(candidate)
+        }
       }
       DEBUG && I.end('Scan for candidates')
     }
 
     if (this.compiler.features & Features.Utilities) {
       DEBUG && I.start('Register dependency messages')
-      // Watch individual files found via custom `@source` paths
-      for (let file of this.scanner.files) {
-        addWatchFile(file)
-      }
+      for (let scanner of [this.scanner, this.explicitScanner]) {
+        if (!scanner) continue
 
-      // Watch globs found via custom `@source` paths
-      for (let glob of this.scanner.globs) {
-        if (glob.pattern[0] === '!') continue
-
-        let relative = path.relative(this.base, glob.base)
-        if (relative[0] !== '.') {
-          relative = './' + relative
+        // Watch individual files found via custom `@source` paths
+        for (let file of scanner.files) {
+          addWatchFile(file)
         }
-        // Ensure relative is a posix style path since we will merge it with the
-        // glob.
-        relative = normalizePath(relative)
 
-        addWatchFile(path.posix.join(relative, glob.pattern))
+        // Watch globs found via custom `@source` paths
+        for (let glob of scanner.globs) {
+          if (glob.pattern[0] === '!') continue
 
-        let root = this.compiler.root
+          let relative = path.relative(this.base, glob.base)
+          if (relative[0] !== '.') {
+            relative = './' + relative
+          }
+          // Ensure relative is a posix style path since we will merge it with the
+          // glob.
+          relative = normalizePath(relative)
 
-        if (root !== 'none' && root !== null) {
-          let basePath = normalizePath(path.resolve(root.base, root.pattern))
+          addWatchFile(path.posix.join(relative, glob.pattern))
 
-          let isDir = await fs.stat(basePath).then(
-            (stats) => stats.isDirectory(),
-            () => false,
-          )
+          let root = this.compiler.root
 
-          if (!isDir) {
-            throw new Error(
-              `The path given to \`source(…)\` must be a directory but got \`source(${basePath})\` instead.`,
+          if (root !== 'none' && root !== null) {
+            let basePath = normalizePath(path.resolve(root.base, root.pattern))
+
+            let isDir = await fs.stat(basePath).then(
+              (stats) => stats.isDirectory(),
+              () => false,
             )
+
+            if (!isDir) {
+              throw new Error(
+                `The path given to \`source(…)\` must be a directory but got \`source(${basePath})\` instead.`,
+              )
+            }
           }
         }
       }