diff --git a/NEWS.md b/NEWS.md
index 9bfc293..e2a356b 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -2,6 +2,7 @@
 
 - Fix: build failure with GCC 4.x
 - Fix: gcc-asan signed integer overflow.
+- Fix: when reading an non supported extra bytes attribute rlas used to print a warning message. It now throws a real warning.
 - Change: use `tinytest` instead of `testthat`
 - New: `read.lasheader()` now reads the extended variable length record (EVLR)
 - New: `write.las()` now writes all GeoKeyDirectoryTag + GeoAsciiParamsTag + GeoDoubleParamsTag
diff --git a/src/rlasstreamer.cpp b/src/rlasstreamer.cpp
index 888fd98..3a7d6cb 100644
--- a/src/rlasstreamer.cpp
+++ b/src/rlasstreamer.cpp
@@ -325,7 +325,10 @@ void RLASstreamer::allocation()
         extra_bytes_attr.push_back(extrabyte);
       }
       else
-        Rprintf("WARNING: data type %d of attribute %d not implemented.\n", extrabyte.data_type, extrabyte.id);
+      {
+        std::string msg = std::string("data type ") + std::to_string(extrabyte.data_type) + std::string(" of extra bytes attribute ") + std::to_string(extrabyte.id) + std::string(" is deprecated and not supported by rlas.");
+        Rf_warningcall(R_NilValue, msg.c_str());
+      }
     }
   }
 }