diff --git a/packages/compiler/src/frontend/lowering/constructor-returns.ts b/packages/compiler/src/frontend/lowering/constructor-returns.ts
index 1cc4c6057..bee2e7567 100644
--- a/packages/compiler/src/frontend/lowering/constructor-returns.ts
+++ b/packages/compiler/src/frontend/lowering/constructor-returns.ts
@@ -153,7 +153,7 @@ function returnsThis(
   const name = callee.name.text;
   const symbol = lowerer.checker.getSymbolAtLocation(callee.name);
   if (symbol === undefined) return false;
-  const methods: ts.Node[] = [...lowerer.checker.declarationsOf(symbol)];
+  const methods: ts.Node[] = [...symbol.declarations];
   if (receiver === ts.SyntaxKind.ThisKeyword) {
     const pending = [...info.subclasses];
     while (pending.length > 0) {
diff --git a/packages/compiler/src/frontend/lowering/lower-stmts.ts b/packages/compiler/src/frontend/lowering/lower-stmts.ts
index 5d8f2ddec..2c36e4973 100644
--- a/packages/compiler/src/frontend/lowering/lower-stmts.ts
+++ b/packages/compiler/src/frontend/lowering/lower-stmts.ts
@@ -2085,7 +2085,7 @@ function javaScriptAnyOrigin(lowerer: Lowerer, node: ts.Expression, depth: numbe
       : expr.expression;
     if (!ts.isIdentifier(callee)) return false;
     const symbol = lowerer.resolveValueSymbol(callee);
-    const declarations = symbol ? lowerer.checker.declarationsOf(symbol) : [];
+    const declarations = symbol ? symbol.declarations : [];
     return (
       declarations.length > 0 &&
       declarations.every((d) => isJsSourceFile(d.getSourceFile()) && ts.isFunctionLike(d))
@@ -2093,7 +2093,7 @@ function javaScriptAnyOrigin(lowerer: Lowerer, node: ts.Expression, depth: numbe
   }
   if (ts.isIdentifier(expr) && depth === 0) {
     const symbol = lowerer.resolveValueSymbol(expr);
-    const declaration = symbol ? lowerer.checker.valueDeclarationOf(symbol) : undefined;
+    const declaration = symbol ? symbol.valueDeclaration : undefined;
     return (
       declaration !== undefined &&
       ts.isVariableDeclaration(declaration) &&
diff --git a/packages/compiler/src/frontend/lowering/lowerer.ts b/packages/compiler/src/frontend/lowering/lowerer.ts
index 85568239f..676496def 100644
--- a/packages/compiler/src/frontend/lowering/lowerer.ts
+++ b/packages/compiler/src/frontend/lowering/lowerer.ts
@@ -3195,8 +3195,7 @@ export class Lowerer {
       const symbol = part.getSymbol();
       return (
         (symbol?.name === "WeakMap" || symbol?.name === "WeakSet") &&
-        this.checker
-          .declarationsOf(symbol)
+        symbol.declarations
           .some((d) => ts.isInterfaceDeclaration(d) && this.isStdlibFile(d.getSourceFile()))
       );
     };
diff --git a/packages/compiler/src/frontend/lowering/module-member-this.ts b/packages/compiler/src/frontend/lowering/module-member-this.ts
index a29e361d9..205cc63e9 100644
--- a/packages/compiler/src/frontend/lowering/module-member-this.ts
+++ b/packages/compiler/src/frontend/lowering/module-member-this.ts
@@ -52,7 +52,7 @@ export function refuseModuleMemberThis(
   if (symbol !== undefined && (symbol.flags & ts.SymbolFlags.Alias) !== 0)
     symbol = lowerer.checker.getAliasedSymbol(symbol);
   if (symbol === undefined) return;
-  for (const decl of lowerer.checker.declarationsOf(symbol)) {
+  for (const decl of symbol.declarations) {
     const fn = exportedFunction(decl);
     if (fn === null || !readsOwnThis(fn)) continue;
     lowerer.unsupported(
diff --git a/packages/compiler/src/frontend/type-mapper.ts b/packages/compiler/src/frontend/type-mapper.ts
index 6a7f14778..47b99c7cb 100644
--- a/packages/compiler/src/frontend/type-mapper.ts
+++ b/packages/compiler/src/frontend/type-mapper.ts
@@ -1360,8 +1360,7 @@ export function mapAsyncGeneratorAnnotation(type: ts.Type, ctx: TypeMapperCtx):
   if (
     !symbol ||
     !["AsyncIterator", "AsyncIterableIterator", "AsyncIterable"].includes(symbol.name) ||
-    !checker
-      .declarationsOf(symbol)
+    !symbol.declarations
       .some((d) => ts.isInterfaceDeclaration(d) && ctx.isStdlibFile(d.getSourceFile()))
   )
     return null;
@@ -2505,8 +2504,7 @@ function mapTypeInner(type: ts.Type, ctx: TypeMapperCtx): IrType | null {
   if (
     psym &&
     WEBCRYPTO_DYN_TYPES.has(psym.name) &&
-    checker
-      .declarationsOf(psym)
+    psym.declarations
       .some(
         (d) =>
           (ts.isClassDeclaration(d) || ts.isInterfaceDeclaration(d)) &&