diff --git a/proxygen/httpclient/samples/H3Datagram/H3DatagramClient.cpp b/proxygen/httpclient/samples/H3Datagram/H3DatagramClient.cpp
index 7ef747ea7d..375654a3be 100644
--- a/proxygen/httpclient/samples/H3Datagram/H3DatagramClient.cpp
+++ b/proxygen/httpclient/samples/H3Datagram/H3DatagramClient.cpp
@@ -147,8 +147,8 @@ class DatagramClient
 int main(int argc, char* argv[]) {
 #if FOLLY_HAVE_LIBGFLAGS
   // Enable glog logging to stderr by default.
-  gflags::SetCommandLineOptionWithMode(
-      "logtostderr", "1", gflags::SET_FLAGS_DEFAULT);
+  folly::gflags::SetCommandLineOptionWithMode(
+      "logtostderr", "1", folly::gflags::SET_FLAGS_DEFAULT);
 #endif
   folly::init(&argc, &argv, false);
 
diff --git a/proxygen/httpclient/samples/curl/CurlClientMain.cpp b/proxygen/httpclient/samples/curl/CurlClientMain.cpp
index 20e78796f1..9d13f8263b 100644
--- a/proxygen/httpclient/samples/curl/CurlClientMain.cpp
+++ b/proxygen/httpclient/samples/curl/CurlClientMain.cpp
@@ -52,8 +52,8 @@ DEFINE_bool(log_response,
 int main(int argc, char* argv[]) {
 #if FOLLY_HAVE_LIBGFLAGS
   // Enable glog logging to stderr by default.
-  gflags::SetCommandLineOptionWithMode(
-      "logtostderr", "1", gflags::SET_FLAGS_DEFAULT);
+  folly::gflags::SetCommandLineOptionWithMode(
+      "logtostderr", "1", folly::gflags::SET_FLAGS_DEFAULT);
 #endif
   auto _ = folly::Init(&argc, &argv, false);