diff --git a/src/main.cpp b/src/main.cpp
index b59fea8..adb8bcf 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -33,6 +33,7 @@
 #include <future>
 #include <iostream>
 #include <locale>
+#include <mutex>
 #include <string>
 #include <string_view>
 #include <thread>
@@ -129,17 +130,21 @@ int main(int argc, char *argv[])
     search_settings.context = opts.context;
 
     vector<vector<search::match>> matches_all;
+    std::mutex mutex_matches_all;
     vector<std::future<int>> futurepool;
 
     auto search_file{
-        [&opts, &matches_all, &search_settings](fs::path filepath)
+        [&opts, &matches_all, &mutex_matches_all,
+         &search_settings](const fs::path &filepath)
         {
             for (const auto &regex : opts.regexp)
             {
                 try
                 {
-                    matches_all.emplace_back(
-                        search::search(filepath, regex, search_settings));
+                    auto matches{
+                        search::search(filepath, regex, search_settings)};
+                    std::lock_guard<std::mutex> guard(mutex_matches_all);
+                    matches_all.emplace_back(matches);
                 }
                 catch (const std::exception &e)
                 {