diff --git a/src/api/f.ts b/src/api/f.ts
index 59c85dc..18f3bd8 100644
--- a/src/api/f.ts
+++ b/src/api/f.ts
@@ -42,6 +42,10 @@ export async function getLoginHash(token: string, timestamp: string | number, us
         signal,
     }).finally(cancel);
 
+    if (response.status !== 200) {
+        throw new ErrorResponse('[s2s] Non-200 status code', response, await response.text());
+    }
+
     const data = await response.json() as LoginHashApiResponse | LoginHashApiError;
 
     if ('error' in data) {
@@ -87,6 +91,10 @@ export async function flapg(
         signal,
     }).finally(cancel);
 
+    if (response.status !== 200) {
+        throw new ErrorResponse('[flapg] Non-200 status code', response, await response.text());
+    }
+
     const data = await response.json() as FlapgApiResponse;
 
     debugFlapg('Got f parameter "%s"', data.result.f);
@@ -160,6 +168,10 @@ export async function iminkf(
         signal,
     }).finally(cancel);
 
+    if (response.status !== 200) {
+        throw new ErrorResponse('[imink] Non-200 status code', response, await response.text());
+    }
+
     const data = await response.json() as IminkFResponse | IminkFError;
 
     if ('error' in data) {
@@ -228,6 +240,10 @@ export async function genf(
         signal,
     }).finally(cancel);
 
+    if (response.status !== 200) {
+        throw new ErrorResponse('[znca-api] Non-200 status code', response, await response.text());
+    }
+
     const data = await response.json() as AndroidZncaFResponse | AndroidZncaFError;
 
     if ('error' in data) {