diff --git a/src/bench/bench.cpp b/src/bench/bench.cpp
--- a/src/bench/bench.cpp
+++ b/src/bench/bench.cpp
@@ -5,6 +5,7 @@
 #include <bench/bench.h>
 
 #include <chainparams.h>
+#include <fs.h>
 #include <validation.h>
 
 #include <test/util/setup_common.h>
@@ -20,7 +21,7 @@
         // nothing to write, bail out
         return;
     }
-    std::ofstream fout(filename);
+    fsbridge::ofstream fout{fs::PathFromString(filename)};
     if (fout.is_open()) {
         ankerl::nanobench::render(tpl, benchmarkResults, fout);
     } else {
diff --git a/src/bitcoin-tx.cpp b/src/bitcoin-tx.cpp
--- a/src/bitcoin-tx.cpp
+++ b/src/bitcoin-tx.cpp
@@ -12,6 +12,7 @@
 #include <consensus/consensus.h>
 #include <core_io.h>
 #include <currencyunit.h>
+#include <fs.h>
 #include <key_io.h>
 #include <primitives/transaction.h>
 #include <rpc/util.h>
@@ -188,7 +189,7 @@
     std::string key = strInput.substr(0, pos);
     std::string filename = strInput.substr(pos + 1, std::string::npos);
 
-    FILE *f = fopen(filename.c_str(), "r");
+    FILE *f = fsbridge::fopen(filename.c_str(), "r");
     if (!f) {
         std::string strErr = "Cannot open file " + filename;
         throw std::runtime_error(strErr);
diff --git a/src/fs.cpp b/src/fs.cpp
--- a/src/fs.cpp
+++ b/src/fs.cpp
@@ -19,6 +19,9 @@
 #include <windows.h>
 #endif
 
+#include <cassert>
+#include <string>
+
 namespace fsbridge {
 
 FILE *fopen(const fs::path &p, const char *mode) {
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -466,8 +466,9 @@
                 if (filename.isEmpty()) {
                     return;
                 }
-                std::ofstream out(filename.toLocal8Bit().data(),
-                                  std::ofstream::out | std::ofstream::binary);
+                fsbridge::ofstream out{filename.toLocal8Bit().data(),
+                                       fsbridge::ofstream::out |
+                                           fsbridge::ofstream::binary};
                 out << ssTx.str();
                 out.close();
                 Q_EMIT message(tr("PSBT saved"), "PSBT saved to disk",
diff --git a/src/qt/walletview.cpp b/src/qt/walletview.cpp
--- a/src/qt/walletview.cpp
+++ b/src/qt/walletview.cpp
@@ -253,7 +253,7 @@
                        CClientUIInterface::MSG_ERROR);
         return;
     }
-    std::ifstream in(filename.toLocal8Bit().data(), std::ios::binary);
+    fsbridge::ifstream in{filename.toLocal8Bit().data(), std::ios::binary};
     std::string dataStr(std::istreambuf_iterator<char>{in}, {});
 
     std::string error;
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -2389,7 +2389,7 @@
     }
 
 #ifdef UPDATE_JSON_TESTS
-    FILE *file = fopen("script_tests.json.gen", "w");
+    FILE *file = fsbridge::fopen("script_tests.json.gen", "w");
     fputs(strGen.c_str(), file);
     fclose(file);
 #endif
diff --git a/src/util/system.cpp b/src/util/system.cpp
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -148,7 +148,7 @@
 }
 
 std::streampos GetFileSize(const char *path, std::streamsize max) {
-    std::ifstream file(path, std::ios::binary);
+    fsbridge::ifstream file{path, std::ios::binary};
     file.ignore(max);
     return file.gcount();
 }