diff -up UpTools-8.5.4/include/UpTools/UpOp.h.s390 UpTools-8.5.4/include/UpTools/UpOp.h
--- UpTools-8.5.4/include/UpTools/UpOp.h.s390	2011-03-25 15:14:26.000000000 +0100
+++ UpTools-8.5.4/include/UpTools/UpOp.h	2011-03-25 15:49:59.000000000 +0100
@@ -66,7 +66,7 @@ std::string& operator<<( std::string& s 
 std::string& operator<<( std::string& s , long long d );
 std::string& operator<<( std::string& s , unsigned long long d );
 std::string& operator<<( std::string& s , bool b );
-#if __WORDSIZE==64
+#if __WORDSIZE==64 || defined(__s390__)
 std::string& operator<<( std::string& s , size_t b );
 #endif
 
@@ -77,7 +77,7 @@ float&              operator<<( float&  
 long long&          operator<<( long long& d         , const std::string& s );
 unsigned long long& operator<<( unsigned long long& d, const std::string& s );
 bool&               operator<<( bool& b              , const std::string& s );
-#if __WORDSIZE==64
+#if __WORDSIZE==64 || defined(__s390__)
 size_t&             operator<<( size_t& b              , const std::string& s );
 #endif
 
diff -up UpTools-8.5.4/UpOp.cc.s390 UpTools-8.5.4/UpOp.cc
--- UpTools-8.5.4/UpOp.cc.s390	2011-03-25 15:14:42.000000000 +0100
+++ UpTools-8.5.4/UpOp.cc	2011-03-25 15:49:19.000000000 +0100
@@ -42,7 +42,7 @@
 
 
 /////////////////////////////////////////////////////////////////////
-#if __WORDSIZE==64
+#if __WORDSIZE==64 || defined(__s390__)
 std::string& operator<<(std::string& s,size_t n) {
 	char buf[32],*p=buf+31; *p=0;
    do { *(--p) = '0'+(n%10); } while(n/=10);
@@ -127,7 +127,7 @@ unsigned long long& operator<<(unsigned 
    return n;
 }
 
-#if __WORDSIZE==64
+#if __WORDSIZE==64 || defined(__s390__)
 size_t& operator<<(size_t& n,const std::string& s) {
 	size_t len = s.size();
    if(len==0) return (n=0);