diff --git a/packages/compiler-core/src/transforms/transformExpression.ts b/packages/compiler-core/src/transforms/transformExpression.ts
index 10637543..8a8734d5 100644
--- a/packages/compiler-core/src/transforms/transformExpression.ts
+++ b/packages/compiler-core/src/transforms/transformExpression.ts
@@ -25,7 +25,7 @@ import {
 } from '../utils'
 import { isGloballyWhitelisted, makeMap } from '@vue/shared'
 
-const isLiteralWhitelisted = makeMap('true,false,null,this')
+const isLiteralWhitelisted = /*@__PURE__*/ makeMap('true,false,null,this')
 
 export const transformExpression: NodeTransform = (node, context) => {
   if (node.type === NodeTypes.INTERPOLATION) {
diff --git a/packages/shared/src/element.ts b/packages/shared/src/element.ts
index 04d5e9fd..27fd813b 100644
--- a/packages/shared/src/element.ts
+++ b/packages/shared/src/element.ts
@@ -23,6 +23,6 @@ const SVG_TAGS =
 const VOID_TAGS =
   'area,base,br,col,embed,hr,img,input,link,meta,param,source,track,wbr'
 
-export const isHTMLTag = makeMap(HTML_TAGS)
-export const isSVGTag = makeMap(SVG_TAGS)
-export const isVoidTag = makeMap(VOID_TAGS)
+export const isHTMLTag = /*@__PURE__*/ makeMap(HTML_TAGS)
+export const isSVGTag = /*@__PURE__*/ makeMap(SVG_TAGS)
+export const isVoidTag = /*@__PURE__*/ makeMap(VOID_TAGS)
diff --git a/packages/shared/src/globalsWhitelist.ts b/packages/shared/src/globalsWhitelist.ts
index 8af8c079..4c0e33a4 100644
--- a/packages/shared/src/globalsWhitelist.ts
+++ b/packages/shared/src/globalsWhitelist.ts
@@ -5,4 +5,4 @@ const GLOBALS_WHITE_LISTED =
   'decodeURIComponent,encodeURI,encodeURIComponent,Math,Number,Date,Array,' +
   'Object,Boolean,String,RegExp,Map,Set,JSON,Intl'
 
-export const isGloballyWhitelisted = makeMap(GLOBALS_WHITE_LISTED)
+export const isGloballyWhitelisted = /*@__PURE__*/ makeMap(GLOBALS_WHITE_LISTED)
diff --git a/packages/shared/src/makeMap.ts b/packages/shared/src/makeMap.ts
index 87291cdd..be9a258a 100644
--- a/packages/shared/src/makeMap.ts
+++ b/packages/shared/src/makeMap.ts
@@ -1,7 +1,8 @@
-/**
- * Make a map and return a function for checking if a key
- * is in that map.
- */
+// Make a map and return a function for checking if a key
+// is in that map.
+//
+// IMPORTANT: all calls of this function must be prefixed with /*@__PURE__*/
+// So that rollup can tree-shake them if necessary.
 export function makeMap(
   str: string,
   expectsLowerCase?: boolean