diff --git a/tools/upend_js/tsconfig.json b/tools/upend_js/tsconfig.json
index 1acd50b..31dda4a 100644
--- a/tools/upend_js/tsconfig.json
+++ b/tools/upend_js/tsconfig.json
@@ -12,7 +12,7 @@
 
     /* Language and Environment */
     "target": "es5",                                     /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
-    "lib": ["es2017"],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
+    "lib": ["es2019"],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
     // "experimentalDecorators": true,                   /* Enable experimental support for TC39 stage 2 draft decorators. */
     // "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
@@ -51,7 +51,7 @@
     // "removeComments": true,                           /* Disable emitting comments. */
     // "noEmit": true,                                   /* Disable emitting files from a compilation. */
     // "importHelpers": true,                            /* Allow importing helper functions from tslib once per project, instead of including them per-file. */
-    // "importsNotUsedAsValues": "remove",               /* Specify emit/checking behavior for imports that are only used for types */
+    "importsNotUsedAsValues": "error",               /* Specify emit/checking behavior for imports that are only used for types */
     // "downlevelIteration": true,                       /* Emit more compliant, but verbose and less performant JavaScript for iteration. */
     // "sourceRoot": "",                                 /* Specify the root path for debuggers to find the reference source code. */
     // "mapRoot": "",                                    /* Specify the location where debugger should locate map files instead of generated locations. */
diff --git a/ui/tsconfig.json b/ui/tsconfig.json
index 9c762d0..f7f6f57 100644
--- a/ui/tsconfig.json
+++ b/ui/tsconfig.json
@@ -1,6 +1,7 @@
 {
   "extends": "@tsconfig/svelte/tsconfig.json",
   "include": ["src/**/*", "node_modules/upend/*"],
+  "exclude": ["**/test.ts"],
   "compilerOptions": {
     "lib": ["es2019"]
   }