diff --git a/src/core/lib/security/credentials/composite/composite_credentials.h b/src/core/lib/security/credentials/composite/composite_credentials.h
index c83f74429f91b8358b21cbfe1ebf7ea16c8b5fd0..96d3b14cc422c3237979eda8b5171e6cda9c9eab 100644
--- a/src/core/lib/security/credentials/composite/composite_credentials.h
+++ b/src/core/lib/security/credentials/composite/composite_credentials.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_COMPOSITE_CREDENTIALS_H
-#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_COMPOSITE_CREDENTIALS_H
+#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_COMPOSITE_COMPOSITE_CREDENTIALS_H
+#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_COMPOSITE_COMPOSITE_CREDENTIALS_H
 
 #include "src/core/lib/security/credentials/credentials.h"
 
@@ -68,5 +68,5 @@ typedef struct {
   grpc_call_credentials_array inner;
 } grpc_composite_call_credentials;
 
-#endif  // GRPC_CORE_LIB_SECURITY_CREDENTIALS_COMPOSITE_CREDENTIALS_H
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_COMPOSITE_COMPOSITE_CREDENTIALS_H */
 
diff --git a/src/core/lib/security/credentials/fake/fake_credentials.h b/src/core/lib/security/credentials/fake/fake_credentials.h
index 10c2a0b5ce6fa42c16f772c59fb89393df8ab876..9cf38084a3df3fdddfa785b1d649d6fef33aee10 100644
--- a/src/core/lib/security/credentials/fake/fake_credentials.h
+++ b/src/core/lib/security/credentials/fake/fake_credentials.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_FAKE_CREDENTIALS_H
-#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_FAKE_CREDENTIALS_H
+#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_FAKE_FAKE_CREDENTIALS_H
+#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_FAKE_FAKE_CREDENTIALS_H
 
 #include "src/core/lib/security/credentials/credentials.h"
 
@@ -40,6 +40,7 @@
 
 /* Creates a fake transport security credentials object for testing. */
 grpc_channel_credentials *grpc_fake_transport_security_credentials_create(void);
+
 /* Creates a fake server transport security credentials object for testing. */
 grpc_server_credentials *grpc_fake_transport_security_server_credentials_create(
     void);
@@ -52,5 +53,4 @@ typedef struct {
   int is_async;
 } grpc_md_only_test_credentials;
 
-#endif  // GRPC_CORE_LIB_SECURITY_CREDENTIALS_FAKE_CREDENTIALS_H
-
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_FAKE_FAKE_CREDENTIALS_H */
diff --git a/src/core/lib/security/credentials/google_default/google_default_credentials.h b/src/core/lib/security/credentials/google_default/google_default_credentials.h
index 33e8c2ec8d6d57eac8771d80bc2ec534b726fac1..fa3f1ae1bf7115962b9ac1ab8b12d25b3964693a 100644
--- a/src/core/lib/security/credentials/google_default/google_default_credentials.h
+++ b/src/core/lib/security/credentials/google_default/google_default_credentials.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_CREDENTIALS_H
-#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_CREDENTIALS_H
+#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_GOOGLE_DEFAULT_CREDENTIALS_H
+#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_GOOGLE_DEFAULT_CREDENTIALS_H
 
 #include "src/core/lib/security/credentials/credentials.h"
 
@@ -42,6 +42,5 @@
 
 void grpc_flush_cached_google_default_credentials(void);
 
-#endif  // GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_CREDENTIALS_H
-
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_GOOGLE_DEFAULT_CREDENTIALS_H */
 
diff --git a/src/core/lib/security/credentials/iam/iam_credentials.h b/src/core/lib/security/credentials/iam/iam_credentials.h
index 7110eaf4781a3ec6d02b5ac63652b56fd15c3625..58b77723fd03e403411a972be9de16e49b7ce2a4 100644
--- a/src/core/lib/security/credentials/iam/iam_credentials.h
+++ b/src/core/lib/security/credentials/iam/iam_credentials.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_IAM_CREDENTIALS_H
-#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_IAM_CREDENTIALS_H
+#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_IAM_IAM_CREDENTIALS_H
+#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_IAM_IAM_CREDENTIALS_H
 
 #include "src/core/lib/security/credentials/credentials.h"
 
@@ -41,7 +41,5 @@ typedef struct {
   grpc_credentials_md_store *iam_md;
 } grpc_google_iam_credentials;
 
-#endif  // GRPC_CORE_LIB_SECURITY_CREDENTIALS_IAM_CREDENTIALS_H
-
-
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_IAM_IAM_CREDENTIALS_H */
 
diff --git a/src/core/lib/security/credentials/jwt/jwt_credentials.h b/src/core/lib/security/credentials/jwt/jwt_credentials.h
index 6faf676414912fc2220e02a8e1abf205df906147..acc73dd47fc60037cd0325b701a529b8c530cb24 100644
--- a/src/core/lib/security/credentials/jwt/jwt_credentials.h
+++ b/src/core/lib/security/credentials/jwt/jwt_credentials.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_JWT_CREDENTIALS_H
-#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_JWT_CREDENTIALS_H
+#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_JWT_JWT_CREDENTIALS_H
+#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_JWT_JWT_CREDENTIALS_H
 
 #include "src/core/lib/security/credentials/credentials.h"
 #include "src/core/lib/security/credentials/jwt/json_token.h"
@@ -59,5 +59,5 @@ grpc_call_credentials *
 grpc_service_account_jwt_access_credentials_create_from_auth_json_key(
     grpc_auth_json_key key, gpr_timespec token_lifetime);
 
-#endif  // GRPC_CORE_LIB_SECURITY_CREDENTIALS_JWT_CREDENTIALS_H
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_JWT_JWT_CREDENTIALS_H */
 
diff --git a/src/core/lib/security/credentials/oauth2/oauth2_credentials.h b/src/core/lib/security/credentials/oauth2/oauth2_credentials.h
index 6cdcc68514e23b9d3f0e9ed1b657d261ad15e81b..4d28fce629df033a80bd592edb19aa9303e85c29 100644
--- a/src/core/lib/security/credentials/oauth2/oauth2_credentials.h
+++ b/src/core/lib/security/credentials/oauth2/oauth2_credentials.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_OAUTH2_CREDENTIALS_H
-#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_OAUTH2_CREDENTIALS_H
+#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_OAUTH2_OAUTH2_CREDENTIALS_H
+#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_OAUTH2_OAUTH2_CREDENTIALS_H
 
 #include "src/core/lib/json/json.h"
 #include "src/core/lib/security/credentials/credentials.h"
@@ -107,5 +107,5 @@ grpc_oauth2_token_fetcher_credentials_parse_server_response(
     const struct grpc_http_response *response,
     grpc_credentials_md_store **token_md, gpr_timespec *token_lifetime);
 
-#endif  // GRPC_CORE_LIB_SECURITY_CREDENTIALS_OAUTH2_CREDENTIALS_H
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_OAUTH2_OAUTH2_CREDENTIALS_H */
 
diff --git a/src/core/lib/security/credentials/plugin/plugin_credentials.h b/src/core/lib/security/credentials/plugin/plugin_credentials.h
index cdabbbd30f76b2a8eceb1ef6d4e770984af95e0e..5b285311524ba14c2f2bb263730b345491e90a3f 100644
--- a/src/core/lib/security/credentials/plugin/plugin_credentials.h
+++ b/src/core/lib/security/credentials/plugin/plugin_credentials.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_PLUGIN_CREDENTIALS_H
-#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_PLUGIN_CREDENTIALS_H
+#ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_PLUGIN_PLUGIN_CREDENTIALS_H
+#define GRPC_CORE_LIB_SECURITY_CREDENTIALS_PLUGIN_PLUGIN_CREDENTIALS_H
 
 #include "src/core/lib/security/credentials/credentials.h"
 
@@ -42,7 +42,5 @@ typedef struct {
   grpc_credentials_md_store *plugin_md;
 } grpc_plugin_credentials;
 
-#endif  // GRPC_CORE_LIB_SECURITY_CREDENTIALS_PLUGIN_CREDENTIALS_H
-
-
+#endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_PLUGIN_PLUGIN_CREDENTIALS_H */
 
diff --git a/src/core/lib/security/util/json_util.h b/src/core/lib/security/util/json_util.h
index 3046412729d96cac55d89e50835ae7a7d077952c..7f3d4659c390194ad8237d65cf08e7fb1cd7daf0 100644
--- a/src/core/lib/security/util/json_util.h
+++ b/src/core/lib/security/util/json_util.h
@@ -53,5 +53,5 @@ bool grpc_copy_json_string_property(const grpc_json *json,
                                     const char *prop_name,
                                     char **copied_value);
 
-#endif  // GRPC_CORE_LIB_SECURITY_UTIL_JSON_UTIL_H
+#endif /* GRPC_CORE_LIB_SECURITY_UTIL_JSON_UTIL_H */
 
diff --git a/tools/dockerfile/grpc_clang_format/Dockerfile b/tools/dockerfile/grpc_clang_format/Dockerfile
index 41239e9c23b3ceb615504b229ab3d3e8804f5bf0..4338b83e32e683ebc976f1f557948eccea480cac 100644
--- a/tools/dockerfile/grpc_clang_format/Dockerfile
+++ b/tools/dockerfile/grpc_clang_format/Dockerfile
@@ -30,9 +30,8 @@
 FROM ubuntu:wily
 RUN apt-get update
 RUN apt-get -y install wget
-RUN echo deb http://llvm.org/apt/wily/ llvm-toolchain-wily main >> /etc/apt/sources.list
-RUN echo deb-src http://llvm.org/apt/wily/ llvm-toolchain-wily main >> /etc/apt/sources.list
-RUN wget -O - http://llvm.org/apt/llvm-snapshot.gpg.key| apt-key add -
+RUN echo deb http://llvm.org/apt/wily/ llvm-toolchain-wily-3.8 main >> /etc/apt/sources.list
+RUN echo deb-src http://llvm.org/apt/wily/ llvm-toolchain-wily-3.8 main >> /etc/apt/sources.list
 RUN apt-get update
 RUN apt-get -y install clang-format-3.8
 ADD clang_format_all_the_things.sh /