diff --git a/lib/frame_file_sink_impl.cc b/lib/frame_file_sink_impl.cc
index 9a988d0..d7c5e13 100644
--- a/lib/frame_file_sink_impl.cc
+++ b/lib/frame_file_sink_impl.cc
@@ -119,8 +119,8 @@ namespace gr
             std::ofstream fd (filename.c_str ());
             su = (uint8_t *) pmt::blob_data (msg);
             for (size_t i = 0; i < pmt::blob_length (msg); i++) {
-              fd << std::hex << std::showbase << std::setw (4)
-                  << (uint32_t) su[i] << " ";
+		fd << "0x" << std::hex << std::setw (2)
+		 << std::setfill('0') << (uint32_t) su[i] << " ";
             }
             fd.close ();
             break;
diff --git a/lib/multi_format_msg_sink_impl.cc b/lib/multi_format_msg_sink_impl.cc
index 9ac46fa..6c156ab 100644
--- a/lib/multi_format_msg_sink_impl.cc
+++ b/lib/multi_format_msg_sink_impl.cc
@@ -66,8 +66,8 @@ namespace gr
         case 1:
           su = (uint8_t *) pmt::blob_data (msg);
           for (size_t i = 0; i < pmt::blob_length (msg); i++) {
-            d_fos << std::hex << std::showbase << std::setw (4)
-                << (uint32_t) su[i] << " ";
+            d_fos << "0x" << std::hex << std::setw (2)
+		 << std::setfill('0') << (uint32_t) su[i] << " ";
           }
           d_fos << std::endl;
           break;