diff --git a/CHANGELOG.md b/CHANGELOG.md
index 67deb410e402..f90e8837d438 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Update types to work with `Node16` module resolution ([#12097](https://github.com/tailwindlabs/tailwindcss/pull/12097))
 - Don’t crash when important and parent selectors are equal in `@apply` ([#12112](https://github.com/tailwindlabs/tailwindcss/pull/12112))
 - Eliminate irrelevant rules when applying variants ([#12113](https://github.com/tailwindlabs/tailwindcss/pull/12113))
+- Improve RegEx parser, reduce possibilities as the key for arbitrary properties ([#12121](https://github.com/tailwindlabs/tailwindcss/pull/12121))
 
 ### Added
 
diff --git a/package-lock.json b/package-lock.json
index 4759326fbb5b..b25e69212614 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -68,7 +68,7 @@
       "name": "@tailwindcss/integrations-content-resolution",
       "version": "0.0.0",
       "devDependencies": {
-        "postcss": "8.4.30",
+        "postcss": "^8.4.30",
         "postcss-cli": "^10.1.0"
       }
     },
@@ -83,7 +83,7 @@
       "name": "@tailwindcss/integrations-postcss-cli",
       "version": "0.0.0",
       "devDependencies": {
-        "postcss": "8.4.30",
+        "postcss": "^8.4.30",
         "postcss-cli": "^10.1.0"
       }
     },
@@ -19061,7 +19061,7 @@
     "@tailwindcss/integrations-content-resolution": {
       "version": "file:integrations/content-resolution",
       "requires": {
-        "postcss": "8.4.30",
+        "postcss": "^8.4.30",
         "postcss-cli": "^10.1.0"
       }
     },
@@ -19074,7 +19074,7 @@
     "@tailwindcss/integrations-postcss-cli": {
       "version": "file:integrations/postcss-cli",
       "requires": {
-        "postcss": "8.4.30",
+        "postcss": "^8.4.30",
         "postcss-cli": "^10.1.0"
       }
     },
@@ -27050,7 +27050,7 @@
         "normalize-path": "^3.0.0",
         "object-hash": "^3.0.0",
         "picocolors": "^1.0.0",
-        "postcss": "^8.4.29",
+        "postcss": "^8.4.30",
         "postcss-import": "^15.1.0",
         "postcss-js": "^4.0.1",
         "postcss-load-config": "^4.0.1",
@@ -29678,7 +29678,7 @@
         "@tailwindcss/integrations-content-resolution": {
           "version": "file:integrations/content-resolution",
           "requires": {
-            "postcss": "8.4.30",
+            "postcss": "^8.4.30",
             "postcss-cli": "^10.1.0"
           }
         },
@@ -29691,7 +29691,7 @@
         "@tailwindcss/integrations-postcss-cli": {
           "version": "file:integrations/postcss-cli",
           "requires": {
-            "postcss": "8.4.30",
+            "postcss": "^8.4.30",
             "postcss-cli": "^10.1.0"
           }
         },
diff --git a/src/lib/defaultExtractor.js b/src/lib/defaultExtractor.js
index 7849fc5f7137..282cc38bc7d0 100644
--- a/src/lib/defaultExtractor.js
+++ b/src/lib/defaultExtractor.js
@@ -11,10 +11,12 @@ export function defaultExtractor(context) {
     let results = []
 
     for (let pattern of patterns) {
-      results = [...results, ...(content.match(pattern) ?? [])]
+      for (let result of content.match(pattern) ?? []) {
+        results.push(clipAtBalancedParens(result))
+      }
     }
 
-    return results.filter((v) => v !== undefined).map(clipAtBalancedParens)
+    return results
   }
 }
 
@@ -33,7 +35,7 @@ function* buildRegExps(context) {
     // This is a targeted fix to continue to allow theme()
     // with square brackets to work in arbitrary properties
     // while fixing a problem with the regex matching too much
-    /\[[^\s:'"`]+:[^\s]+?\[[^\s]+\][^\s]+?\]/,
+    /\[[^\s:'"`\]]+:[^\s]+?\[[^\s]+\][^\s]+?\]/,
 
     // Utilities
     regex.pattern([
diff --git a/tests/parse-candidate-strings.test.js b/tests/parse-candidate-strings.test.js
index a97d66846236..cc0b1002de1f 100644
--- a/tests/parse-candidate-strings.test.js
+++ b/tests/parse-candidate-strings.test.js
@@ -438,4 +438,25 @@ describe.each([
       expect(extractions).not.toContain(`bold`)
     })
   })
+
+  describe('real world', () => {
+    it.each([
+      [
+        'const myCVAComponent = cva([],{defaultVariants:{size:"md"},variants:{size:{sm:["p-1"],md:["p-1.5"],lg:["p-2"],xl:["p-2.5"]}}});',
+      ],
+      [
+        'const myCVAComponent = cva([],{defaultVariants:{size:"md"}, variants:{size:{sm:["p-1"],md:["p-1.5"],lg:["p-2"],xl:["p-2.5"]}}});',
+      ],
+      [
+        'const myCVAComponent = cva("",{defaultVariants:{size:"md"},variants:{size:{sm:["p-1"],md:["p-1.5"],lg:["p-2"],xl:["p-2.5"]}}});',
+      ],
+    ])('should work for issue #12109 (%#)', async (content) => {
+      let extractions = parse(content)
+
+      expect(extractions).toContain('p-1')
+      expect(extractions).toContain('p-1.5')
+      expect(extractions).toContain('p-2')
+      expect(extractions).toContain('p-2.5')
+    })
+  })
 })