diff --git a/packages/packem/packem.config.ts b/packages/packem/packem.config.ts
index 2164cd58a..6979a4ae4 100644
--- a/packages/packem/packem.config.ts
+++ b/packages/packem/packem.config.ts
@@ -5,7 +5,7 @@ import isolatedDeclarationTransformer from "./src/rollup/plugins/typescript/isol
 // eslint-disable-next-line import/no-unused-modules
 export default defineConfig({
     cjsInterop: true,
-    fileCache: false,
+    fileCache: true,
     isolatedDeclarationTransformer,
     rollup: {
         license: {
diff --git a/packages/packem/src/rollup/build.ts b/packages/packem/src/rollup/build.ts
index 989c1203c..461c07fa7 100644
--- a/packages/packem/src/rollup/build.ts
+++ b/packages/packem/src/rollup/build.ts
@@ -17,7 +17,9 @@ const build = async (context: BuildContext, fileCache: FileCache, subDirectory:
         return;
     }
 
-    rollupOptions.cache = fileCache.get<RollupCache>(BUNDLE_CACHE_KEY, subDirectory);
+    if (!context.options.rollup.isolatedDeclarations || !context.options.isolatedDeclarationTransformer) {
+        rollupOptions.cache = fileCache.get<RollupCache>(BUNDLE_CACHE_KEY, subDirectory);
+    }
 
     const buildResult = await rollup(rollupOptions);
 
diff --git a/packages/packem/src/rollup/watch.ts b/packages/packem/src/rollup/watch.ts
index 97a4a368e..aba131d74 100644
--- a/packages/packem/src/rollup/watch.ts
+++ b/packages/packem/src/rollup/watch.ts
@@ -84,7 +84,9 @@ const watch = async (context: BuildContext, fileCache: FileCache): Promise<void>
         return;
     }
 
-    rollupOptions.cache = fileCache.get<RollupCache>(WATCH_CACHE_KEY);
+    if (!context.options.rollup.isolatedDeclarations || !context.options.isolatedDeclarationTransformer) {
+        rollupOptions.cache = fileCache.get<RollupCache>(WATCH_CACHE_KEY);
+    }
 
     if (context.options.rollup.watch && typeof rollupOptions.watch === "object" && rollupOptions.watch.include === undefined) {
         rollupOptions.watch = {
diff --git a/packages/packem/tsconfig.json b/packages/packem/tsconfig.json
index b364647ea..2504a5671 100644
--- a/packages/packem/tsconfig.json
+++ b/packages/packem/tsconfig.json
@@ -1,7 +1,7 @@
 {
     "$schema": "https://json.schemastore.org/tsconfig",
     "extends": "../../tsconfig.base.json",
-    "include": ["src/**/*", "*.d.ts"],
+    "include": ["src/**/*", "*.d.ts", "./packem.config.ts"],
     "compilerOptions": {
         "moduleResolution": "Bundler"
     }
diff --git a/tsconfig.base.json b/tsconfig.base.json
index 15486c13f..21015f723 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -50,9 +50,9 @@
         "skipLibCheck": true,
         "forceConsistentCasingInFileNames": true,
 
-        "allowJs": false,
-        "checkJs": false,
-        "isolatedDeclarations": true,
+        "allowJs": true,
+        "checkJs": true,
+        "isolatedDeclarations": false,
         "noErrorTruncation": true
     },
     "exclude": ["dist/**/*", "node_modules/**/*", "build/**/*", "scripts/**/*", "examples/**", "**/coverage/**"]