diff --git a/opm/autodiff/FlowMainEbos.hpp b/opm/autodiff/FlowMainEbos.hpp
index ddce566a7..04fdaee66 100755
--- a/opm/autodiff/FlowMainEbos.hpp
+++ b/opm/autodiff/FlowMainEbos.hpp
@@ -326,8 +326,16 @@ namespace Opm
             std::ostringstream debugFileStream;
             std::ostringstream logFileStream;
 
-            // Strip extension if any
-            baseName = boost::to_upper_copy(path(fpath.stem()).string());
+            // Strip extension "." or ".DATA"
+            std::string extension = boost::to_upper_copy(fpath.extension().string());
+            if ( extension == ".DATA" || extension == "." )
+            {
+                baseName = boost::to_upper_copy(fpath.stem().string());
+            }
+            else
+            {
+                baseName = boost::to_upper_copy(fpath.filename().string());
+            }
 
             const std::string& output_dir = eclState().getIOConfig().getOutputDir();
             logFileStream << output_dir << "/" << baseName;
@@ -427,7 +435,17 @@ namespace Opm
             const std::string& output_dir = eclState().getIOConfig().getOutputDir();
             fs::path output_path(output_dir);
             fs::path deck_filename(EWOMS_GET_PARAM(TypeTag, std::string, EclDeckFileName));
-            std::string basename = boost::to_upper_copy(fs::path(deck_filename).stem().string());
+            std::string basename;
+            // Strip extension "." and ".DATA"
+            std::string extension = boost::to_upper_copy(deck_filename.extension().string());
+            if ( extension == ".DATA" || extension == "." )
+            {
+                basename = boost::to_upper_copy(deck_filename.stem().string());
+            }
+            else
+            {
+                basename = boost::to_upper_copy(deck_filename.filename().string());
+            }
             std::for_each(fs::directory_iterator(output_path),
                           fs::directory_iterator(),
                           detail::ParallelFileMerger(output_path, basename,