diff --git a/src/get-bulk-daily-package-downloads.ts b/src/get-bulk-daily-package-downloads.ts
index 976e1d0..d8c9162 100644
--- a/src/get-bulk-daily-package-downloads.ts
+++ b/src/get-bulk-daily-package-downloads.ts
@@ -1,7 +1,7 @@
 import urlJoin from "url-join";
 import { z } from "zod";
 import { assertValidPackageName } from "./assert-valid-package-name";
-import { DownloadPeriod } from "./download-period";
+import type { DownloadPeriod } from "./download-period";
 import { fetchData } from "./fetch-data";
 import { DailyPackageDownloads } from "./get-daily-package-downloads";
 import { npmRegistryDownloadsApiUrl } from "./npm-registry";
diff --git a/src/get-bulk-package-downloads.ts b/src/get-bulk-package-downloads.ts
index 85fcd15..bf42a22 100644
--- a/src/get-bulk-package-downloads.ts
+++ b/src/get-bulk-package-downloads.ts
@@ -1,7 +1,7 @@
 import urlJoin from "url-join";
 import { z } from "zod";
 import { assertValidPackageName } from "./assert-valid-package-name";
-import { DownloadPeriod } from "./download-period";
+import type { DownloadPeriod } from "./download-period";
 import { fetchData } from "./fetch-data";
 import { PackageDownloads } from "./get-package-downloads";
 import { npmRegistryDownloadsApiUrl } from "./npm-registry";
diff --git a/src/get-daily-package-downloads.ts b/src/get-daily-package-downloads.ts
index 8da6f82..f32862f 100644
--- a/src/get-daily-package-downloads.ts
+++ b/src/get-daily-package-downloads.ts
@@ -1,7 +1,7 @@
 import urlJoin from "url-join";
 import { z } from "zod";
 import { assertValidPackageName } from "./assert-valid-package-name";
-import { DownloadPeriod } from "./download-period";
+import type { DownloadPeriod } from "./download-period";
 import { fetchData } from "./fetch-data";
 import { DailyRegistryDownloads } from "./get-daily-registry-downloads";
 import { npmRegistryDownloadsApiUrl } from "./npm-registry";
diff --git a/src/get-daily-registry-downloads.ts b/src/get-daily-registry-downloads.ts
index 8a63657..668a005 100644
--- a/src/get-daily-registry-downloads.ts
+++ b/src/get-daily-registry-downloads.ts
@@ -1,6 +1,6 @@
 import urlJoin from "url-join";
 import { z } from "zod";
-import { DownloadPeriod } from "./download-period";
+import type { DownloadPeriod } from "./download-period";
 import { fetchData } from "./fetch-data";
 import { npmRegistryDownloadsApiUrl } from "./npm-registry";
 
diff --git a/src/get-package-downloads.ts b/src/get-package-downloads.ts
index d1c8f51..1347cb6 100644
--- a/src/get-package-downloads.ts
+++ b/src/get-package-downloads.ts
@@ -1,7 +1,7 @@
 import urlJoin from "url-join";
 import { z } from "zod";
 import { assertValidPackageName } from "./assert-valid-package-name";
-import { DownloadPeriod } from "./download-period";
+import type { DownloadPeriod } from "./download-period";
 import { fetchData } from "./fetch-data";
 import { RegistryDownloads } from "./get-registry-downloads";
 import { npmRegistryDownloadsApiUrl } from "./npm-registry";
diff --git a/src/get-registry-downloads.ts b/src/get-registry-downloads.ts
index 95044c6..c76166a 100644
--- a/src/get-registry-downloads.ts
+++ b/src/get-registry-downloads.ts
@@ -1,6 +1,6 @@
 import urlJoin from "url-join";
 import { z } from "zod";
-import { DownloadPeriod } from "./download-period";
+import type { DownloadPeriod } from "./download-period";
 import { fetchData } from "./fetch-data";
 import { npmRegistryDownloadsApiUrl } from "./npm-registry";