diff --git a/src/FatUtils.h b/src/FatUtils.h
index 5080f2a..a8d69ee 100644
--- a/src/FatUtils.h
+++ b/src/FatUtils.h
@@ -32,13 +32,13 @@ using namespace std;
 
 // trim from start
 static inline string ltrim(string s) {
-  s.erase(s.begin(), find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace))));
+  s.erase(s.begin(), find_if(s.begin(), s.end(), [](unsigned char c) {return !isspace(c);}));
   return s;
 }
 
 // trim from end
 static inline string rtrim(string s) {
-  s.erase(find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(), s.end());
+  s.erase(find_if(s.rbegin(), s.rend(), [](unsigned char c) {return !isspace(c);}).base(), s.end());
   return s;
 }