diff --git a/fuzz/cert.cc b/fuzz/cert.cc
index b27237b8d1..0bfcac4cb1 100644
--- a/fuzz/cert.cc
+++ b/fuzz/cert.cc
@@ -19,10 +19,10 @@
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *buf, size_t len) {
   X509 *x509 = d2i_X509(NULL, &buf, len);
   if (x509 != NULL) {
-    /* Extract the public key. */
+    // Extract the public key.
     EVP_PKEY_free(X509_get_pubkey(x509));
 
-    /* Reserialize the structure. */
+    // Reserialize the structure.
     uint8_t *der = NULL;
     i2d_X509(x509, &der);
     OPENSSL_free(der);
diff --git a/tool/internal.h b/tool/internal.h
index a3d608af2b..a6c8ecab37 100644
--- a/tool/internal.h
+++ b/tool/internal.h
@@ -90,4 +90,4 @@ extern const uint8_t kDERRSAPrivate4096[];
 extern const size_t kDERRSAPrivate4096Len;
 
 
-#endif /* !OPENSSL_HEADER_TOOL_INTERNAL_H */
+#endif  // !OPENSSL_HEADER_TOOL_INTERNAL_H
diff --git a/tool/speed.cc b/tool/speed.cc
index cf7e70e806..87aa2de990 100644
--- a/tool/speed.cc
+++ b/tool/speed.cc
@@ -153,9 +153,9 @@ static bool SpeedRSA(const std::string &key_name, RSA *key,
   TimeResults results;
   if (!TimeFunction(&results,
                     [key, &sig, &fake_sha256_hash, &sig_len]() -> bool {
-        /* Usually during RSA signing we're using a long-lived |RSA| that has
-         * already had all of its |BN_MONT_CTX|s constructed, so it makes
-         * sense to use |key| directly here. */
+        // Usually during RSA signing we're using a long-lived |RSA| that has
+        // already had all of its |BN_MONT_CTX|s constructed, so it makes
+        // sense to use |key| directly here.
         return RSA_sign(NID_sha256, fake_sha256_hash, sizeof(fake_sha256_hash),
                         sig.get(), &sig_len, key);
       })) {
@@ -167,11 +167,11 @@ static bool SpeedRSA(const std::string &key_name, RSA *key,
 
   if (!TimeFunction(&results,
                     [key, &fake_sha256_hash, &sig, sig_len]() -> bool {
-        /* Usually during RSA verification we have to parse an RSA key from a
-         * certificate or similar, in which case we'd need to construct a new
-         * RSA key, with a new |BN_MONT_CTX| for the public modulus. If we were
-         * to use |key| directly instead, then these costs wouldn't be
-         * accounted for. */
+        // Usually during RSA verification we have to parse an RSA key from a
+        // certificate or similar, in which case we'd need to construct a new
+        // RSA key, with a new |BN_MONT_CTX| for the public modulus. If we were
+        // to use |key| directly instead, then these costs wouldn't be
+        // accounted for.
         bssl::UniquePtr<RSA> verify_key(RSA_new());
         if (!verify_key) {
           return false;
diff --git a/tool/transport_common.h b/tool/transport_common.h
index b1496716c5..0bc6053ac3 100644
--- a/tool/transport_common.h
+++ b/tool/transport_common.h
@@ -65,4 +65,4 @@ bool DoSMTPStartTLS(int sock);
 // success and false otherwise.
 bool DoHTTPTunnel(int sock, const std::string &hostname_and_port);
 
-#endif  /* !OPENSSL_HEADER_TOOL_TRANSPORT_COMMON_H */
+#endif  // !OPENSSL_HEADER_TOOL_TRANSPORT_COMMON_H