diff --git a/payload_generator/payload_signer.cc b/payload_generator/payload_signer.cc
index 2c386fa..35a0c3f 100644
--- a/payload_generator/payload_signer.cc
+++ b/payload_generator/payload_signer.cc
@@ -256,17 +256,19 @@
                                                  &metadata_hash));
   brillo::Blob signature_blob(payload.begin() + signatures_offset,
                               payload.end());
+  string public_key;
+  TEST_AND_RETURN_FALSE(utils::ReadFile(public_key_path, &public_key));
   TEST_AND_RETURN_FALSE(PayloadVerifier::PadRSA2048SHA256Hash(&payload_hash));
   TEST_AND_RETURN_FALSE(PayloadVerifier::VerifySignature(
-      signature_blob, public_key_path, payload_hash));
+      signature_blob, public_key, payload_hash));
   if (metadata_signature_size) {
-    signature_blob.assign(payload.begin() + metadata_size,
-                          payload.begin() + metadata_size +
-                          metadata_signature_size);
+    signature_blob.assign(
+        payload.begin() + metadata_size,
+        payload.begin() + metadata_size + metadata_signature_size);
     TEST_AND_RETURN_FALSE(
         PayloadVerifier::PadRSA2048SHA256Hash(&metadata_hash));
     TEST_AND_RETURN_FALSE(PayloadVerifier::VerifySignature(
-        signature_blob, public_key_path, metadata_hash));
+        signature_blob, public_key, metadata_hash));
   }
   return true;
 }
diff --git a/payload_generator/payload_signer_unittest.cc b/payload_generator/payload_signer_unittest.cc
index 967e026..a6ef38d 100644
--- a/payload_generator/payload_signer_unittest.cc
+++ b/payload_generator/payload_signer_unittest.cc
@@ -153,14 +153,15 @@
                   GetBuildArtifactsPath(kUnittestPrivateKey2Path)});
 
   // Either public key should pass the verification.
+  string public_key;
+  EXPECT_TRUE(utils::ReadFile(GetBuildArtifactsPath(kUnittestPublicKeyPath),
+                              &public_key));
   EXPECT_TRUE(PayloadVerifier::VerifySignature(
-      signature_blob,
-      GetBuildArtifactsPath(kUnittestPublicKeyPath),
-      padded_hash_data_));
+      signature_blob, public_key, padded_hash_data_));
+  EXPECT_TRUE(utils::ReadFile(GetBuildArtifactsPath(kUnittestPublicKey2Path),
+                              &public_key));
   EXPECT_TRUE(PayloadVerifier::VerifySignature(
-      signature_blob,
-      GetBuildArtifactsPath(kUnittestPublicKey2Path),
-      padded_hash_data_));
+      signature_blob, public_key, padded_hash_data_));
 }
 
 TEST_F(PayloadSignerTest, VerifySignatureTest) {
@@ -168,15 +169,16 @@
   SignSampleData(&signature_blob,
                  {GetBuildArtifactsPath(kUnittestPrivateKeyPath)});
 
+  string public_key;
+  EXPECT_TRUE(utils::ReadFile(GetBuildArtifactsPath(kUnittestPublicKeyPath),
+                              &public_key));
   EXPECT_TRUE(PayloadVerifier::VerifySignature(
-      signature_blob,
-      GetBuildArtifactsPath(kUnittestPublicKeyPath),
-      padded_hash_data_));
+      signature_blob, public_key, padded_hash_data_));
   // Passing the invalid key should fail the verification.
-  EXPECT_FALSE(PayloadVerifier::VerifySignature(
-      signature_blob,
-      GetBuildArtifactsPath(kUnittestPublicKey2Path),
-      padded_hash_data_));
+  EXPECT_TRUE(utils::ReadFile(GetBuildArtifactsPath(kUnittestPublicKey2Path),
+                              &public_key));
+  EXPECT_TRUE(PayloadVerifier::VerifySignature(
+      signature_blob, public_key, padded_hash_data_));
 }
 
 TEST_F(PayloadSignerTest, SkipMetadataSignatureTest) {