diff --git a/src/curl.cpp b/src/curl.cpp
index 8733c55..6bfb7b5 100644
--- a/src/curl.cpp
+++ b/src/curl.cpp
@@ -36,6 +36,7 @@
 #include <libxml/tree.h>
 #include <iostream>
 #include <fstream>
+#include <sstream>
 #include <string>
 #include <map>
 #include <algorithm>
@@ -4130,8 +4131,8 @@ string prepare_url(const char* url)
   string uri;
   string host;
   string path;
-  string url_str = str(url);
-  string token =  str("/" + bucket);
+  string url_str = string(url);
+  string token = string("/") + bucket;
   int bucket_pos = url_str.find(token);
   int bucket_length = token.size();
   int uri_length = 0;
@@ -4159,7 +4160,7 @@ string prepare_url(const char* url)
 
   S3FS_PRN_INFO3("URL changed is %s", url_str.c_str());
 
-  return str(url_str);
+  return url_str;
 }
 
 /*
diff --git a/src/string_util.cpp b/src/string_util.cpp
index cd897ed..cb5b6ef 100644
--- a/src/string_util.cpp
+++ b/src/string_util.cpp
@@ -32,6 +32,21 @@
 
 using namespace std;
 
+template <class T> std::string str(T value) {
+  std::stringstream s;
+  s << value;
+  return s.str();
+}
+
+template std::string str(short value);
+template std::string str(unsigned short value);
+template std::string str(int value);
+template std::string str(unsigned int value);
+template std::string str(long value);
+template std::string str(unsigned long value);
+template std::string str(long long value);
+template std::string str(unsigned long long value);
+
 static const char hexAlphabet[] = "0123456789ABCDEF";
 
 off_t s3fs_strtoofft(const char* str, bool is_base_16)
diff --git a/src/string_util.h b/src/string_util.h
index 5557a38..5011772 100644
--- a/src/string_util.h
+++ b/src/string_util.h
@@ -28,16 +28,11 @@
 #include <sys/types.h>
 
 #include <string>
-#include <sstream>
 
 #define SPACES                " \t\r\n"
 #define STR2NCMP(str1, str2)  strncmp(str1, str2, strlen(str2))
 
-template<typename T> std::string str(T value) {
-  std::stringstream s;
-  s << value;
-  return s.str();
-}
+template <class T> std::string str(T value);
 
 off_t s3fs_strtoofft(const char* str, bool is_base_16 = false);