diff --git a/lib/Target/JSBackend/JSBackend.cpp b/lib/Target/JSBackend/JSBackend.cpp
index d959102..f96ad7e 100644
--- a/lib/Target/JSBackend/JSBackend.cpp
+++ b/lib/Target/JSBackend/JSBackend.cpp
@@ -14,6 +14,7 @@
 //
 //===----------------------------------------------------------------------===//

+#include "tostr.h"
 #include "JSTargetMachine.h"
 #include "MCTargetDesc/JSBackendMCTargetDesc.h"
 #include "AllocaManager.h"
diff --git a/lib/Target/JSBackend/tostr.h b/lib/Target/JSBackend/tostr.h
new file mode 100644
index 0000000..4ef386e
--- /dev/null
+++ b/lib/Target/JSBackend/tostr.h
@@ -0,0 +1,16 @@
+#include <string>
+#include <sstream>
+
+namespace std
+{
+
+static std::string to_string(int a)
+{
+  std::stringstream ss;
+
+  ss << a;
+
+  return ss.str();
+}
+
+}
diff --git a/tools/sancov/sancov.cc b/tools/sancov/sancov.cc
index 55b0370..ecaaaff 100644
--- a/tools/sancov/sancov.cc
+++ b/tools/sancov/sancov.cc
@@ -10,6 +10,7 @@
 // This file is a command-line tool for reading and analyzing sanitizer
 // coverage.
 //===----------------------------------------------------------------------===//
+#include "tostr.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/DebugInfo/Symbolize/Symbolize.h"
diff --git a/tools/sancov/tostr.h b/tools/sancov/tostr.h
new file mode 100644
index 0000000..4ef386e
--- /dev/null
+++ b/tools/sancov/tostr.h
@@ -0,0 +1,16 @@
+#include <string>
+#include <sstream>
+
+namespace std
+{
+
+static std::string to_string(int a)
+{
+  std::stringstream ss;
+
+  ss << a;
+
+  return ss.str();
+}
+
+}