diff --git a/src/iperf_api.c b/src/iperf_api.c
index 7fb741e77..35647f77b 100644
--- a/src/iperf_api.c
+++ b/src/iperf_api.c
@@ -4457,6 +4457,7 @@ iperf_new_stream(struct iperf_test *test, int s, int sender)
         return NULL;
     }
     sp->pending_size = 0;
+    sp->thread_number = 0;
 
     /* Set socket */
     sp->socket = s;
diff --git a/src/iperf_client_api.c b/src/iperf_client_api.c
index 7af54f7aa..a498abc78 100644
--- a/src/iperf_client_api.c
+++ b/src/iperf_client_api.c
@@ -742,22 +742,28 @@ iperf_run_client(struct iperf_test * test)
                     if (sp->sender) {
                         int rc;
                         sp->done = 1;
-                        rc = pthread_cancel(sp->thr);
-                        if (rc != 0 && rc != ESRCH) {
-                            i_errno = IEPTHREADCANCEL;
-                            errno = rc;
-                            iperf_err(test, "sender cancel in pthread_cancel of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
-                            goto cleanup_and_fail;
-                        }
-                        rc = pthread_join(sp->thr, NULL);
-                        if (rc != 0 && rc != ESRCH) {
-                            i_errno = IEPTHREADJOIN;
-                            errno = rc;
-                            iperf_err(test, "sender cancel in pthread_join of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
-                            goto cleanup_and_fail;
-                        }
-                        if (test->debug_level >= DEBUG_LEVEL_INFO) {
-                            iperf_printf(test, "Thread number %d FD %d stopped\n", sp->thread_number, sp->socket);
+                        if (sp->thread_number > 0) { // if thread was created
+                            rc = pthread_cancel(sp->thr);
+                            if (rc != 0 && rc != ESRCH) {
+                                i_errno = IEPTHREADCANCEL;
+                                errno = rc;
+                                iperf_err(test, "sender cancel in pthread_cancel of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
+                                goto cleanup_and_fail;
+                            }
+                            rc = pthread_join(sp->thr, NULL);
+                            if (rc != 0 && rc != ESRCH) {
+                                i_errno = IEPTHREADJOIN;
+                                errno = rc;
+                                iperf_err(test, "sender cancel in pthread_join of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
+                                goto cleanup_and_fail;
+                            }
+                            if (test->debug_level >= DEBUG_LEVEL_INFO) {
+                                iperf_printf(test, "Thread number %d FD %d stopped\n", sp->thread_number, sp->socket);
+                            }
+                            sp->thread_number = 0;
+                        } else {
+                            if (test->debug_level >= DEBUG_LEVEL_INFO)
+                                iperf_printf(test, "Not stopping thread for FD %d as it was not created\n", sp->socket);
                         }
                     }
                 }
@@ -788,22 +794,28 @@ iperf_run_client(struct iperf_test * test)
         if (!sp->sender) {
             int rc;
             sp->done = 1;
-            rc = pthread_cancel(sp->thr);
-            if (rc != 0 && rc != ESRCH) {
-                i_errno = IEPTHREADCANCEL;
-                errno = rc;
-                iperf_err(test, "receiver cancel in pthread_cancel of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
-                goto cleanup_and_fail;
-            }
-            rc = pthread_join(sp->thr, NULL);
-            if (rc != 0 && rc != ESRCH) {
-                i_errno = IEPTHREADJOIN;
-                errno = rc;
-                iperf_err(test, "receiver cancel in pthread_join of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
-                goto cleanup_and_fail;
-            }
-            if (test->debug_level >= DEBUG_LEVEL_INFO) {
-                iperf_printf(test, "Thread number %d FD %d stopped\n", sp->thread_number, sp->socket);
+            if (sp->thread_number > 0) { // if thread was created
+                rc = pthread_cancel(sp->thr);
+                if (rc != 0 && rc != ESRCH) {
+                    i_errno = IEPTHREADCANCEL;
+                    errno = rc;
+                    iperf_err(test, "receiver cancel in pthread_cancel of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
+                    goto cleanup_and_fail;
+                }
+                rc = pthread_join(sp->thr, NULL);
+                if (rc != 0 && rc != ESRCH) {
+                    i_errno = IEPTHREADJOIN;
+                    errno = rc;
+                    iperf_err(test, "receiver cancel in pthread_join of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
+                    goto cleanup_and_fail;
+                }
+                if (test->debug_level >= DEBUG_LEVEL_INFO) {
+                    iperf_printf(test, "Thread number %d FD %d stopped\n", sp->thread_number, sp->socket);
+                }
+                sp->thread_number = 0;
+            } else {
+                if (test->debug_level >= DEBUG_LEVEL_INFO)
+                    iperf_printf(test, "Not stopping thread for FD %d as it was not created\n", sp->socket);
             }
         }
     }
@@ -829,20 +841,26 @@ iperf_run_client(struct iperf_test * test)
     SLIST_FOREACH(sp, &test->streams, streams) {
         sp->done = 1;
         int rc;
-        rc = pthread_cancel(sp->thr);
-        if (rc != 0 && rc != ESRCH) {
-            i_errno = IEPTHREADCANCEL;
-            errno = rc;
-            iperf_err(test, "cleanup_and_fail in pthread_cancel of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
-        }
-        rc = pthread_join(sp->thr, NULL); 
-        if (rc != 0 && rc != ESRCH) {
-            i_errno = IEPTHREADJOIN;
-            errno = rc;
-            iperf_err(test, "cleanup_and_fail in pthread_join of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
-        }
-        if (test->debug_level >= DEBUG_LEVEL_INFO) {
-            iperf_printf(test, "Thread number %d FD %d stopped\n", sp->thread_number, sp->socket);
+        if (sp->thread_number > 0) { // if thread was created
+            rc = pthread_cancel(sp->thr);
+            if (rc != 0 && rc != ESRCH) {
+                i_errno = IEPTHREADCANCEL;
+                errno = rc;
+                iperf_err(test, "cleanup_and_fail in pthread_cancel of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
+            }
+            rc = pthread_join(sp->thr, NULL); 
+            if (rc != 0 && rc != ESRCH) {
+                i_errno = IEPTHREADJOIN;
+                errno = rc;
+                iperf_err(test, "cleanup_and_fail in pthread_join of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
+            }
+            if (test->debug_level >= DEBUG_LEVEL_INFO) {
+                iperf_printf(test, "Thread number %d FD %d stopped\n", sp->thread_number, sp->socket);
+            }
+            sp->thread_number = 0;
+        } else {
+            if (test->debug_level >= DEBUG_LEVEL_INFO)
+                iperf_printf(test, "Not stopping thread for FD %d as it was not created\n", sp->socket);
         }
     }
     if (test->debug_level >= DEBUG_LEVEL_INFO) {
diff --git a/src/iperf_sctp.c b/src/iperf_sctp.c
index 104083281..e36d49d89 100644
--- a/src/iperf_sctp.c
+++ b/src/iperf_sctp.c
@@ -70,7 +70,7 @@ iperf_sctp_recv(struct iperf_stream *sp)
 	sp->result->bytes_received_this_interval += r;
     }
     else {
-	if (sp->test->debug)
+	if (sp->test->debug_level >= DEBUG_LEVEL_DEBUG)
 	    printf("Late receive, state = %d\n", sp->test->state);
     }
 
diff --git a/src/iperf_server_api.c b/src/iperf_server_api.c
index d29f85ead..cb7e328b3 100644
--- a/src/iperf_server_api.c
+++ b/src/iperf_server_api.c
@@ -428,20 +428,26 @@ cleanup_server(struct iperf_test *test)
     SLIST_FOREACH(sp, &test->streams, streams) {
         int rc;
         sp->done = 1;
-        rc = pthread_cancel(sp->thr);
-        if (rc != 0 && rc != ESRCH) {
-            i_errno = IEPTHREADCANCEL;
-            errno = rc;
-            iperf_err(test, "cleanup_server in pthread_cancel of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
-        }
-        rc = pthread_join(sp->thr, NULL);
-        if (rc != 0 && rc != ESRCH) {
-            i_errno = IEPTHREADJOIN;
-            errno = rc;
-            iperf_err(test, "cleanup_server in pthread_join of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
-        }
-        if (test->debug_level >= DEBUG_LEVEL_INFO) {
-            iperf_printf(test, "Thread number %d FD %d stopped\n", sp->thread_number, sp->socket);
+        if (sp->thread_number > 0) { // if thread was created
+            rc = pthread_cancel(sp->thr);
+            if (rc != 0 && rc != ESRCH) {
+                i_errno = IEPTHREADCANCEL;
+                errno = rc;
+                iperf_err(test, "cleanup_server in pthread_cancel of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
+            }
+            rc = pthread_join(sp->thr, NULL);
+            if (rc != 0 && rc != ESRCH) {
+                i_errno = IEPTHREADJOIN;
+                errno = rc;
+                iperf_err(test, "cleanup_server in pthread_join of thread %d - %s", sp->thread_number, iperf_strerror(i_errno));
+            }
+            if (test->debug_level >= DEBUG_LEVEL_INFO) {
+                iperf_printf(test, "Thread number %d FD %d stopped\n", sp->thread_number, sp->socket);
+            }
+            sp->thread_number = 0;
+        } else {
+            if (test->debug_level >= DEBUG_LEVEL_INFO)
+                iperf_printf(test, "Not stopping thread for FD %d as it was not created\n", sp->socket);
         }
     }
     i_errno = i_errno_save;
diff --git a/src/iperf_tcp.c b/src/iperf_tcp.c
index 71c40a6ea..877635d99 100644
--- a/src/iperf_tcp.c
+++ b/src/iperf_tcp.c
@@ -68,7 +68,7 @@ iperf_tcp_recv(struct iperf_stream *sp)
 	sp->result->bytes_received_this_interval += r;
     }
     else {
-	if (sp->test->debug)
+	if (sp->test->debug_level >= DEBUG_LEVEL_DEBUG)
 	    printf("Late receive, state = %d\n", sp->test->state);
     }
 
diff --git a/src/iperf_udp.c b/src/iperf_udp.c
index a603236df..825eae9fe 100644
--- a/src/iperf_udp.c
+++ b/src/iperf_udp.c
@@ -183,7 +183,7 @@ iperf_udp_recv(struct iperf_stream *sp)
 	sp->jitter += (d - sp->jitter) / 16.0;
     }
     else {
-	if (sp->test->debug)
+	if (sp->test->debug_level >= DEBUG_LEVEL_DEBUG)
 	    printf("Late receive, state = %d\n", sp->test->state);
     }