diff --git a/CHANGELOG.md b/CHANGELOG.md
index 96d38c1b1b1a..46ba7a7c30f8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Add missing `main` and `browser` fields for `@tailwindcss/browser` ([#15594](https://github.com/tailwindlabs/tailwindcss/pull/15594))
 - _Upgrade (experimental)_: Pretty print `--spacing(…)` to prevent ambiguity ([#15596](https://github.com/tailwindlabs/tailwindcss/pull/15596))
+- Discard invalid variants such as `data-checked-[selected=1]:*` ([#15629](https://github.com/tailwindlabs/tailwindcss/pull/15629))
 
 ## [4.0.0-beta.9] - 2025-01-09
 
diff --git a/packages/tailwindcss/src/candidate.test.ts b/packages/tailwindcss/src/candidate.test.ts
index 848590a46a88..723ae0fc8e08 100644
--- a/packages/tailwindcss/src/candidate.test.ts
+++ b/packages/tailwindcss/src/candidate.test.ts
@@ -836,6 +836,63 @@ it('should not parse invalid arbitrary values', () => {
   }
 })
 
+it('should not parse invalid arbitrary values in variants', () => {
+  let utilities = new Utilities()
+  utilities.static('flex', () => [])
+
+  let variants = new Variants()
+  variants.functional('data', () => {})
+
+  for (let candidate of [
+    'data-foo-[#0088cc]:flex',
+    'data-foo[#0088cc]:flex',
+
+    'data-foo-[color:var(--value)]:flex',
+    'data-foo[color:var(--value)]:flex',
+
+    'data-foo-[#0088cc]/50:flex',
+    'data-foo[#0088cc]/50:flex',
+
+    'data-foo-[#0088cc]/[50%]:flex',
+    'data-foo[#0088cc]/[50%]:flex',
+
+    'data-foo-[#0088cc]:flex!',
+    'data-foo[#0088cc]:flex!',
+
+    'data-foo-[var(--value)]:flex',
+    'data-foo[var(--value)]:flex',
+
+    'data-foo-[var(--value)]:flex!',
+    'data-foo[var(--value)]:flex!',
+
+    'data-foo-(color:--value):flex',
+    'data-foo(color:--value):flex',
+
+    'data-foo-(color:--value)/50:flex',
+    'data-foo(color:--value)/50:flex',
+
+    'data-foo-(color:--value)/(--mod):flex',
+    'data-foo(color:--value)/(--mod):flex',
+
+    'data-foo-(color:--value)/(number:--mod):flex',
+    'data-foo(color:--value)/(number:--mod):flex',
+
+    'data-foo-(--value):flex',
+    'data-foo(--value):flex',
+
+    'data-foo-(--value)/50:flex',
+    'data-foo(--value)/50:flex',
+
+    'data-foo-(--value)/(--mod):flex',
+    'data-foo(--value)/(--mod):flex',
+
+    'data-foo-(--value)/(number:--mod):flex',
+    'data-foo(--value)/(number:--mod):flex',
+  ]) {
+    expect(run(candidate, { utilities, variants })).toEqual([])
+  }
+})
+
 it('should parse a utility with an implicit variable as the modifier', () => {
   let utilities = new Utilities()
   utilities.functional('bg', () => [])
@@ -966,6 +1023,18 @@ it('should parse a utility with an explicit variable as the modifier that is imp
   `)
 })
 
+it('should not parse a partial variant', () => {
+  let utilities = new Utilities()
+  utilities.static('flex', () => [])
+
+  let variants = new Variants()
+  variants.static('open', () => {})
+  variants.functional('data', () => {})
+
+  expect(run('open-:flex', { utilities, variants })).toMatchInlineSnapshot(`[]`)
+  expect(run('data-:flex', { utilities, variants })).toMatchInlineSnapshot(`[]`)
+})
+
 it('should parse a static variant starting with @', () => {
   let utilities = new Utilities()
   utilities.static('flex', () => [])
diff --git a/packages/tailwindcss/src/candidate.ts b/packages/tailwindcss/src/candidate.ts
index 6c15b2ba6163..abb230da005d 100644
--- a/packages/tailwindcss/src/candidate.ts
+++ b/packages/tailwindcss/src/candidate.ts
@@ -620,7 +620,10 @@ export function parseVariant(variant: string, designSystem: DesignSystem): Varia
             }
           }
 
-          if (value[0] === '[' && value[value.length - 1] === ']') {
+          if (value[value.length - 1] === ']') {
+            // Discard values like `foo-[#bar]`
+            if (value[0] !== '[') continue
+
             let arbitraryValue = decodeArbitraryValue(value.slice(1, -1))
 
             // Empty arbitrary values are invalid. E.g.: `data-[]:`
@@ -638,7 +641,10 @@ export function parseVariant(variant: string, designSystem: DesignSystem): Varia
             }
           }
 
-          if (value[0] === '(' && value[value.length - 1] === ')') {
+          if (value[value.length - 1] === ')') {
+            // Discard values like `foo-(--bar)`
+            if (value[0] !== '(') continue
+
             let arbitraryValue = decodeArbitraryValue(value.slice(1, -1))
 
             // Empty arbitrary values are invalid. E.g.: `data-():`