diff --git a/src/StreamEpics.cc b/src/StreamEpics.cc
index b3ebbfe..845f922 100644
--- a/src/StreamEpics.cc
+++ b/src/StreamEpics.cc
@@ -18,6 +18,7 @@
 *                                                              *
 ***************************************************************/
 
+#include <errno.h>
 #include "StreamCore.h"
 #include "StreamError.h"
 
@@ -237,6 +238,24 @@ long streamReload(const char* recordname)
     return OK;
 }
 
+long streamSetLogfile(const char* filename)
+{
+    FILE *oldfile, *newfile = NULL;
+    if (filename)
+    {
+        newfile = fopen(filename, "w");
+        if (!newfile)
+        {
+            fprintf(stderr, "Opening file %s failed: %s\n", filename, strerror(errno));
+            return ERROR;
+        }
+    }
+    oldfile = StreamDebugFile;
+    StreamDebugFile = newfile;
+    if (oldfile) fclose(oldfile);
+    return OK;
+}
+
 #ifndef EPICS_3_13
 static const iocshArg streamReloadArg0 =
     { "recordname", iocshArgString };
@@ -262,10 +281,23 @@ void streamReportRecordFunc (const iocshArgBuf *args)
     streamReportRecord(args[0].sval);
 }
 
+static const iocshArg streamSetLogfileArg0 =
+    { "filename", iocshArgString };
+static const iocshArg * const streamSetLogfileArgs[] =
+    { &streamSetLogfileArg0 };
+static const iocshFuncDef streamSetLogfileDef =
+    { "streamSetLogfile", 1, streamSetLogfileArgs };
+
+void streamSetLogfileFunc (const iocshArgBuf *args)
+{
+    streamSetLogfile(args[0].sval);
+}
+
 static void streamRegistrar ()
 {
     iocshRegister(&streamReloadDef, streamReloadFunc);
     iocshRegister(&streamReportRecordDef, streamReportRecordFunc);
+    iocshRegister(&streamSetLogfileDef, streamSetLogfileFunc);
     // make streamReload available for subroutine records
     registryFunctionAdd("streamReload",
         (REGISTRYFUNCTION)streamReloadSub);
@@ -276,6 +308,8 @@ static void streamRegistrar ()
 extern "C" {
 epicsExportRegistrar(streamRegistrar);
 }
+
+
 #endif // !EPICS_3_13
 
 // driver support ////////////////////////////////////////////////////////
diff --git a/streamApp/Makefile b/streamApp/Makefile
index 4e790c5..bbf3620 100644
--- a/streamApp/Makefile
+++ b/streamApp/Makefile
@@ -60,10 +60,6 @@ endif
 
 PROD_LIBS += $(EPICS_BASE_IOC_LIBS)
 
-# Write StreamDevice debug output to this file
-# If unset output goes to stdout
-CPPFLAGS += -DDEBUGFILE=StreamDebug.log
-
 # switch off annoying rset warnings in 3.16+
 CPPFLAGS += -DUSE_TYPED_RSET
 
@@ -74,6 +70,6 @@ clean:
 else
 clean::
 endif
-	$(RM) core* StreamDebug.log
+	$(RM) core* *.log
 
 endif
diff --git a/streamApp/example.cmd b/streamApp/example.cmd
index e22d9fc..0544d85 100755
--- a/streamApp/example.cmd
+++ b/streamApp/example.cmd
@@ -32,6 +32,9 @@ asynOctetSetOutputEos "terminal",0,"\r\n"
 #load the records
 dbLoadRecords "example.db","PREFIX=DZ"
 
+#log debug output to file
+#streamSetLogfile StreamDebug.log
+
 #lots(!) of debug output before iocInit
 #var streamDebug 1
 
diff --git a/streamApp/regexp.cmd b/streamApp/regexp.cmd
index 479eccd..99e850f 100755
--- a/streamApp/regexp.cmd
+++ b/streamApp/regexp.cmd
@@ -8,6 +8,9 @@ drvAsynIPPortConfigure web epics.web.psi.ch:80 0 1
 
 dbLoadRecords regexp.db
 
+#log debug output to file
+#streamSetLogfile StreamDebug.log
+
 iocInit
 #var streamDebug 1
 
diff --git a/streamApp/simple.cmd b/streamApp/simple.cmd
index 7aa4b7a..d5dc6d8 100755
--- a/streamApp/simple.cmd
+++ b/streamApp/simple.cmd
@@ -14,7 +14,10 @@ drvAsynIPPortConfigure "L0", "localhost:40000"
 #load the records
 dbLoadRecords "simple.db","P=DZ,BUS=L0 28"
 
+#log debug output to file
+#streamSetLogfile StreamDebug.log
+
 iocInit
 
 #enable debug output
-var streamDebug 1
+#var streamDebug 1
diff --git a/streamApp/streamAppMain.cc b/streamApp/streamAppMain.cc
index 31a74d5..a952e4a 100644
--- a/streamApp/streamAppMain.cc
+++ b/streamApp/streamAppMain.cc
@@ -19,15 +19,9 @@
 
 #include "epicsThread.h"
 #include "iocsh.h"
-#include "devStream.h"
 
 int main(int argc,char *argv[])
 {
-#ifdef DEBUGFILE
-#define STR2(x) #x
-#define STR(x) STR2(x)
-    StreamDebugFile = fopen(STR(DEBUGFILE), "w");
-#endif
     if(argc>=2) {
         iocsh(argv[1]);
         epicsThreadSleep(.2);
diff --git a/streamApp/test.cmd b/streamApp/test.cmd
index f98f59f..b55000c 100755
--- a/streamApp/test.cmd
+++ b/streamApp/test.cmd
@@ -8,5 +8,10 @@ epicsEnvSet "STREAM_PROTOCOL_PATH", "."
 drvAsynIPPortConfigure "terminal", "localhost:40000"
 
 dbLoadRecords "test.db","P=TEST"
+
+#log debug output to file
+#streamSetLogfile StreamDebug.log
+
 iocInit
+
 #var streamDebug 1