diff --git a/tests/rigctl.c b/tests/rigctl.c
index c90064686..8adc9c34e 100644
--- a/tests/rigctl.c
+++ b/tests/rigctl.c
@@ -151,6 +151,10 @@ int main(int argc, char *argv[])
     int ext_resp = 0;
     int i;
     char rigstartup[1024];
+    char vbuf[1024];
+
+    int err = setvbuf(stderr, vbuf, _IOFBF, sizeof(vbuf));
+    if (err) rig_debug(RIG_DEBUG_ERR, "%s: setvbuf err=%s\n", __func__, strerror(err));
 
     while (1)
     {
diff --git a/tests/rigctld.c b/tests/rigctld.c
index 364569a64..5686a2929 100644
--- a/tests/rigctld.c
+++ b/tests/rigctld.c
@@ -267,6 +267,7 @@ int main(int argc, char *argv[])
     char host[NI_MAXHOST];
     char serv[NI_MAXSERV];
     char rigstartup[1024];
+    char vbuf[1024];
 #if HAVE_SIGACTION
     struct sigaction act;
 #endif
@@ -282,6 +283,10 @@ int main(int argc, char *argv[])
 
     is_rigctld = 1;
 
+    int err = setvbuf(stderr, vbuf, _IOFBF, sizeof(vbuf));
+    if (err) rig_debug(RIG_DEBUG_ERR, "%s: setvbuf err=%s\n", __func__, strerror(err));
+
+
     while (1)
     {
         int c;