diff --git a/tests/unit/libfetchers/data/public-key/noRoundTrip.json b/tests/unit/libfetchers/data/public-key/noRoundTrip.json
new file mode 100644
index 000000000..4dcbf9148
--- /dev/null
+++ b/tests/unit/libfetchers/data/public-key/noRoundTrip.json
@@ -0,0 +1,3 @@
+{
+  "key": "ABCDE"
+}
diff --git a/tests/unit/libfetchers/public-key.cc b/tests/unit/libfetchers/public-key.cc
index 941ae9db7..7b763bb05 100644
--- a/tests/unit/libfetchers/public-key.cc
+++ b/tests/unit/libfetchers/public-key.cc
@@ -42,4 +42,13 @@ TEST_JSON(PublicKeyTest, simple, (fetchers::PublicKey { .type = "ssh-rsa", .key
 TEST_JSON(PublicKeyTest, defaultType, fetchers::PublicKey { .key = "ABCDE" })
 
 #undef TEST_JSON
+
+TEST_F(PublicKeyTest, PublicKey_noRoundTrip_from_json) {
+    readTest("noRoundTrip.json", [&](const auto & encoded_) {
+        fetchers::PublicKey expected = { .type = "ssh-ed25519", .key = "ABCDE" };
+        fetchers::PublicKey got = nlohmann::json::parse(encoded_);
+        ASSERT_EQ(got, nlohmann::json(expected));
+    });
+}
+
 }