diff --git a/xplat/Sonar/SonarWebSocketImpl.cpp b/xplat/Sonar/SonarWebSocketImpl.cpp
index 26419b99d..cc81efcc4 100644
--- a/xplat/Sonar/SonarWebSocketImpl.cpp
+++ b/xplat/Sonar/SonarWebSocketImpl.cpp
@@ -42,6 +42,8 @@ static constexpr int insecurePort = 8089;
 namespace facebook {
 namespace sonar {
 
+bool fileExists(std::string fileName);
+
 class ConnectionEvents : public rsocket::RSocketConnectionEvents {
  private:
   SonarWebSocketImpl* websocket_;
@@ -249,6 +251,9 @@ void SonarWebSocketImpl::requestSignedCertFromSonar() {
 }
 
 std::string SonarWebSocketImpl::loadStringFromFile(std::string fileName) {
+  if (!fileExists(fileName)) {
+    return "";
+  }
   std::stringstream buffer;
   std::ifstream stream;
   std::string line;
@@ -283,5 +288,10 @@ bool SonarWebSocketImpl::ensureSonarDirExists() {
   }
 }
 
+bool fileExists(std::string fileName) {
+  struct stat buffer;
+  return stat(fileName.c_str(), &buffer) == 0;
+}
+
 } // namespace sonar
 } // namespace facebook