diff --git a/tests/infra/crypto.py b/tests/infra/crypto.py
index d8066556191a..6efb24ae267c 100644
--- a/tests/infra/crypto.py
+++ b/tests/infra/crypto.py
@@ -70,6 +70,7 @@ def generate_aes_key(key_bits: int) -> bytes:
 
 
 def generate_rsa_keypair(key_size: int) -> Tuple[str, str]:
+    assert key_size >= 2048
     priv = rsa.generate_private_key(
         public_exponent=RECOMMENDED_RSA_PUBLIC_EXPONENT,
         key_size=key_size,
diff --git a/tests/npm_tests.py b/tests/npm_tests.py
index 99e1aae4cffd..85cb37b5bab7 100644
--- a/tests/npm_tests.py
+++ b/tests/npm_tests.py
@@ -78,7 +78,7 @@ def generate_and_verify_jwk(client):
         assert body["pem"] == pub_pem
 
     # RSA
-    key_sizes = [1024, 2048, 4096]
+    key_sizes = [2048, 4096]
     for key_size in key_sizes:
         priv_pem, pub_pem = infra.crypto.generate_rsa_keypair(key_size)