diff --git a/.gitignore b/.gitignore
index 679f3749bf..e769546527 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,9 +7,11 @@
 
 # Compiler output
 /lit-html.d.ts
+/lit-html.d.ts.map
 /lit-html.js
 /lit-html.js.map
 /test/**/*.d.ts
+/test/**/*.d.ts.map
 /test/**/*.js
 /test/**/*.js.map
 
diff --git a/package.json b/package.json
index 8628659c3a..afd5f776f9 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,7 @@
     "/lit-html.js",
     "/lit-html.js.map",
     "/lit-html.d.ts",
+    "/lit-html.d.ts.map",
     "/lib/",
     "/directives/",
     "/src/",
diff --git a/tsconfig.json b/tsconfig.json
index 1e473859fb..e5ddaac9bb 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,6 +4,7 @@
     "module": "es2015",
     "lib": ["es2017", "esnext.asynciterable", "dom"],
     "declaration": true,
+    "declarationMap": true,
     "sourceMap": true,
     "inlineSources": true,
     "outDir": "./",