diff --git a/cmake/cpplint.cmake b/cmake/cpplint.cmake
index 48f705818b70c92adef107fd3c973ae1ab3d34bb..6bbcd730e1b5ac49415cac676352e6df00eb6eb5 100644
--- a/cmake/cpplint.cmake
+++ b/cmake/cpplint.cmake
@@ -25,6 +25,7 @@ set(STYLE_FILTER "${STYLE_FILTER}-readability/casting")
 set(IGNORE_PATTERN
     .*ImportanceSampler.*
     .*cblas\\.h.*
+    .*\\.pb\\.txt
     .*LtrDataProvider.*
     .*MultiDataProvider.*)
 
diff --git a/go/pserver/cclient/test/test_cclient.c b/go/pserver/cclient/test/test_cclient.c
index b16769b433e72188d411ba1bf2586a3702434324..8eababbe33914d25f1eb91b991e11eaacd2e4716 100644
--- a/go/pserver/cclient/test/test_cclient.c
+++ b/go/pserver/cclient/test/test_cclient.c
@@ -51,7 +51,7 @@ int main() {
   char *config_proto;
   size_t config_proto_len = 0;
   ssize_t nread;
-  FILE *fp = fopen("testdata/optimizer.pb.txt", "r");
+  FILE *fp = fopen("testdata/optimizer.pb", "r");
   if (!fp) {
     fail();
   }
diff --git a/go/pserver/cclient/test/testdata/optimizer.pb b/go/pserver/cclient/test/testdata/optimizer.pb
new file mode 100644
index 0000000000000000000000000000000000000000..27dd3bc5f19e2964b4b674cff8860233cbdb445a
Binary files /dev/null and b/go/pserver/cclient/test/testdata/optimizer.pb differ
diff --git a/go/pserver/cclient/test/testdata/optimizer.pb.txt b/go/pserver/cclient/test/testdata/optimizer.pb.txt
deleted file mode 100644
index 27c8a584df40ab714edfd730f0ff7b7bd3783964..0000000000000000000000000000000000000000
Binary files a/go/pserver/cclient/test/testdata/optimizer.pb.txt and /dev/null differ
diff --git a/go/pserver/client_test.go b/go/pserver/client_test.go
index a248a3fb696a1e03b799f89afceb255de68662b1..b805efa921630098f7ee2fcce8c02722d57d7485 100644
--- a/go/pserver/client_test.go
+++ b/go/pserver/client_test.go
@@ -75,7 +75,7 @@ func TestClientFull(t *testing.T) {
 	}
 
 	const numParameter = 100
-	config, err := ioutil.ReadFile("./cclient/test/testdata/optimizer.pb.txt")
+	config, err := ioutil.ReadFile("./cclient/test/testdata/optimizer.pb")
 	if err != nil {
 		t.Fatalf("read optimizer proto failed")
 	}
diff --git a/go/pserver/optimizer_test.go b/go/pserver/optimizer_test.go
index 368047d6f89e080016909efbc5bd090c42530bfd..b99b5a5f0bfed4d780ea19b75ddaa4129be77bd5 100644
--- a/go/pserver/optimizer_test.go
+++ b/go/pserver/optimizer_test.go
@@ -11,7 +11,7 @@ func TestOptimizerCreateRelease(t *testing.T) {
 		ElementType: Int32,
 	}
 	p.Content = []byte{1, 3}
-	config, err := ioutil.ReadFile("./cclient/test/testdata/optimizer.pb.txt")
+	config, err := ioutil.ReadFile("./cclient/test/testdata/optimizer.pb")
 	if err != nil {
 		t.Fatalf("read optimizer proto failed")
 	}
diff --git a/go/pserver/service_test.go b/go/pserver/service_test.go
index f86619447c28b5be8071d28a127b48768939261b..30e3ac8ae1ccd1d6c9e71ed113cc2543e8c1e224 100644
--- a/go/pserver/service_test.go
+++ b/go/pserver/service_test.go
@@ -19,7 +19,7 @@ func TestServiceFull(t *testing.T) {
 	p.Name = "param_a"
 	p.Content = []byte{1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0}
 	p.ElementType = pserver.Int32
-	config, err := ioutil.ReadFile("./cclient/test/testdata/optimizer.pb.txt")
+	config, err := ioutil.ReadFile("./cclient/test/testdata/optimizer.pb")
 	if err != nil {
 		t.Fatalf("read optimizer proto failed")
 	}
@@ -149,7 +149,7 @@ func TestBlockUntilInitialized(t *testing.T) {
 	p.Name = "param_a"
 	p.Content = []byte{1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0}
 	p.ElementType = pserver.Int32
-	config, err := ioutil.ReadFile("./cclient/test/testdata/optimizer.pb.txt")
+	config, err := ioutil.ReadFile("./cclient/test/testdata/optimizer.pb")
 	if err != nil {
 		t.Fatalf("read optimizer proto failed")
 	}