diff --git a/.npmignore b/.npmignore
new file mode 100644
index 000000000..9db083158
--- /dev/null
+++ b/.npmignore
@@ -0,0 +1 @@
+*.test.*
diff --git a/src/steps/writing/creation/rootFiles.ts b/src/steps/writing/creation/rootFiles.ts
index c5ea67ed4..9c9229401 100644
--- a/src/steps/writing/creation/rootFiles.ts
+++ b/src/steps/writing/creation/rootFiles.ts
@@ -25,6 +25,7 @@ export async function createRootFiles(options: Options) {
 				"node_modules/",
 			]),
 		}),
+		".npmignore": `*.test.*\n`,
 		".nvmrc": `20.12.2\n`,
 		".prettierignore": formatIgnoreFile([
 			...(options.excludeAllContributors ? [] : [".all-contributorsrc"]),