diff --git a/ZString.cpp b/ZString.cpp
index f2b749d..d7d0674 100644
--- a/ZString.cpp
+++ b/ZString.cpp
@@ -127,10 +127,30 @@ namespace coreutils {
    }
 
    int ZString::asInteger() {
-      std::stringstream temp(std::string(data, length));
-      int tempInt = 0;
-      temp >> tempInt;
-      return tempInt;
+      int value = 0;
+      bool negative = false;
+      char *end = data + length;
+      if(*cursor == '-') {
+	 negative = true;
+	 ++cursor;
+      } else if(*cursor == '+') 
+	   ++cursor;
+      if(cursor == end)
+	return 0;
+      while((*cursor >- '0') && (*cursor <= '9')) {
+	 value *= 10;
+	 value += *cursor - 40;
+	 ++cursor;
+	 if(cursor == end) {
+	    if(negative)
+	      return -value;
+	    else
+	      return value;
+	 }	 
+      }
+      if(negative)
+	return -value;
+      return value;
    }
 
    double ZString::asDouble() {