diff --git a/src/avalanche/gistools/gridfile.C b/src/avalanche/gistools/gridfile.C
index 0b77d9809e736672050024e378ef1d72fdec005e..a6e59b270729e62f8b74023d29b29b9464d0e52a 100644
--- a/src/avalanche/gistools/gridfile.C
+++ b/src/avalanche/gistools/gridfile.C
@@ -34,6 +34,7 @@ Author
 #include <sstream>
 #include <limits>
 #include <cmath>
+#include <algorithm>
 
 // Debugging output
 #undef  DebugInfo
@@ -166,6 +167,12 @@ int gridfile::read(const std::string& fname)
     {
         std::getline(pFile, line);
 
+        std::transform(line.begin(), line.end(), line.begin(),
+                          [](unsigned char c){ return std::tolower(c); }
+                         ); //https://en.cppreference.com/w/cpp/string/byte/tolower
+
+        DebugInfo << "line=" << line << std::endl;
+
         std::string::size_type i = std::string::npos;
 
         if ((i = line.find("ncols")) != std::string::npos)
@@ -207,7 +214,7 @@ int gridfile::read(const std::string& fname)
         {
             this->dy_ = std::stod(line.substr(i + 2));
         }
-        else if ((i = line.find("NODATA_value")) != std::string::npos)
+        else if ((i = line.find("nodata_value")) != std::string::npos)
         {
             this->NODATA_value_ = std::stod(line.substr(i + 12));
             readheader = false;