diff --git a/packages/tailwindcss/src/compile.ts b/packages/tailwindcss/src/compile.ts
index deca45e85..d1dc7d0ee 100644
--- a/packages/tailwindcss/src/compile.ts
+++ b/packages/tailwindcss/src/compile.ts
@@ -24,7 +24,7 @@ export function compileCandidates(
       if (throwOnInvalidCandidate) {
         throw new Error(`Cannot apply unknown utility class: ${rawCandidate}`)
       }
-      designSystem.invalidRawCandidates.add(rawCandidate)
+      designSystem.markInvalidCandidate(rawCandidate)
       continue // Bail, invalid candidate
     }
     candidates.set(candidate, rawCandidate)
@@ -42,7 +42,7 @@ export function compileCandidates(
       if (throwOnInvalidCandidate) {
         throw new Error(`Cannot apply unknown utility class: ${rawCandidate}`)
       }
-      designSystem.invalidRawCandidates.add(rawCandidate)
+      designSystem.markInvalidCandidate(rawCandidate)
       continue next
     }
 
diff --git a/packages/tailwindcss/src/design-system.ts b/packages/tailwindcss/src/design-system.ts
index dd844a4f5..fa6390f0a 100644
--- a/packages/tailwindcss/src/design-system.ts
+++ b/packages/tailwindcss/src/design-system.ts
@@ -25,7 +25,8 @@ export type DesignSystem = {
   getUsedVariants(): ReturnType<typeof parseVariant>[]
   getAstNodeSize(): number
 
-  invalidRawCandidates: Set<string>
+  markInvalidCandidate(candidate: string): void
+  isInvalidCandidate(candidate: string): boolean
 }
 
 export function buildDesignSystem(theme: Theme): DesignSystem {
@@ -41,7 +42,6 @@ export function buildDesignSystem(theme: Theme): DesignSystem {
     theme,
     utilities,
     variants,
-    invalidRawCandidates,
 
     candidatesToCss(classes: string[]) {
       let result: (string | null)[] = []
@@ -83,6 +83,13 @@ export function buildDesignSystem(theme: Theme): DesignSystem {
     getAstNodeSize() {
       return compiledAstNodes.size
     },
+
+    markInvalidCandidate(candidate: string) {
+      invalidRawCandidates.add(candidate)
+    },
+    isInvalidCandidate(candidate: string) {
+      return invalidRawCandidates.has(candidate)
+    },
   }
 
   return designSystem
diff --git a/packages/tailwindcss/src/index.ts b/packages/tailwindcss/src/index.ts
index 193d97453..d5205bd52 100644
--- a/packages/tailwindcss/src/index.ts
+++ b/packages/tailwindcss/src/index.ts
@@ -179,7 +179,7 @@ export function compile(
   // and should be ignored.
   let allValidCandidates = new Set<string>()
   for (let rawCandidate of rawCandidates) {
-    if (!designSystem.invalidRawCandidates.has(rawCandidate)) {
+    if (!designSystem.isInvalidCandidate(rawCandidate)) {
       allValidCandidates.add(rawCandidate)
     }
   }
@@ -190,7 +190,7 @@ export function compile(
       // Add all new candidates unless we know that they are invalid.
       let previousSize = allValidCandidates.size
       for (let candidate of newRawCandidates) {
-        if (!designSystem.invalidRawCandidates.has(candidate)) {
+        if (!designSystem.isInvalidCandidate(candidate)) {
           allValidCandidates.add(candidate)
         }
       }