diff --git a/src/StreamBuffer.cc b/src/StreamBuffer.cc
index 2181667..97f430e 100644
--- a/src/StreamBuffer.cc
+++ b/src/StreamBuffer.cc
@@ -317,7 +317,7 @@ dump() const
     for (i = 0; i < cap; i++)
     {
         if (i == offs) result.append("\033[34m[\033[0m");
-        if ((buffer[i] & 0x7f) < 0x20 || (buffer[i] & 0x7f) == 0x7f)
+        if (buffer[i] < 0x20 || buffer[i] >= 0x7f)
         {
             if (i < offs || i >= offs+len)
             result.print(
diff --git a/streamApp/tests/streamtestlib.tcl b/streamApp/tests/streamtestlib.tcl
index 47e42e2..08db47b 100644
--- a/streamApp/tests/streamtestlib.tcl
+++ b/streamApp/tests/streamtestlib.tcl
@@ -61,6 +61,7 @@ proc startioc {} {
         puts $fd "dbLoadDatabase ../O.Common/streamApp.dbd"
         puts $fd "streamApp_registerRecordDeviceDriver"
     }
+    puts $fd "streamSetLogfile StreamDebug.log"
     puts $fd "epicsEnvSet STREAM_PROTOCOL_PATH ."
     puts $fd "drvAsynIPPortConfigure device localhost:$port"
     puts $fd "dbLoadRecords test.db"
@@ -172,7 +173,7 @@ proc escape {string} {
             append result "\\r"
         } elseif {$n == 10} {
             append result "\\n"
-        } elseif {($n & 127) < 32} {
+        } elseif {$n < 32 || $n >= 127} {
             append result [format "<%02x>" $n]
         } else {
             append result $c