diff --git a/clang-tools-extra/clangd/tool/ClangdMain.cpp b/clang-tools-extra/clangd/tool/ClangdMain.cpp
index 39f2185359ad..f22dd35e901c 100644
--- a/clang-tools-extra/clangd/tool/ClangdMain.cpp
+++ b/clang-tools-extra/clangd/tool/ClangdMain.cpp
@@ -259,6 +259,9 @@ int main(int argc, char *argv[]) {
   if (Tracer)
     TracingSession.emplace(*Tracer);
 
+  // Use buffered stream to stderr (we still flush each log message). Unbuffered
+  // stream can cause significant (non-deterministic) latency for the logger.
+  llvm::errs().SetBuffered();
   JSONOutput Out(llvm::outs(), llvm::errs(), LogLevel,
                  InputMirrorStream ? InputMirrorStream.getPointer() : nullptr,
                  PrettyPrint);