--- a/include/fcgio.h
+++ b/include/fcgio.h
@@ -77,10 +77,10 @@ protected:
     virtual int sync();
 
     // Remove and return the current character.
-    virtual int uflow();
+    virtual int_type uflow();
 
     // Fill the get area (if buffered) and return the current character.
-    virtual int underflow();
+    virtual int_type underflow();
 
     // Use a buffer.  The only reasons that a buffer would be useful is
     // to support the use of the unget()/putback() or seek() methods.  Using
--- a/libfcgi/fcgio.cpp
+++ b/libfcgi/fcgio.cpp
@@ -86,7 +86,7 @@ int fcgi_streambuf::sync()
 }
 
 // uflow() removes the char, underflow() doesn't
-int fcgi_streambuf::uflow() 
+std::basic_streambuf<char>::int_type fcgi_streambuf::uflow()
 {
     if (this->bufsize)
     {
@@ -100,7 +100,7 @@ int fcgi_streambuf::uflow()
     }
 }
 				
-int fcgi_streambuf::underflow()
+std::basic_streambuf<char>::int_type fcgi_streambuf::underflow()
 {
     if (this->bufsize)
     {