diff --git a/scripts/get-put.test b/scripts/get-put.test
index 10a30561..1c29fc79 100755
--- a/scripts/get-put.test
+++ b/scripts/get-put.test
@@ -45,12 +45,14 @@ READY_COUNTER=0
 
 
 wait_for_server() {
-    while [ ! -s "$READY_FILE" ] && [ "$READY_COUNTER" -lt 20 ]; do
+    while [ ! -s "$READY_FILE" ] && [ "$READY_COUNTER" -lt 100 ]; do
         sleep 0.1
         READY_COUNTER=$((READY_COUNTER+ 1))
     done
 
-    if test -e "$READY_FILE"
+    # -s, not -e: the echoserver creates the file empty and writes the
+    # port afterward, so -e can catch it mid-write and yield no port
+    if [ -s "$READY_FILE" ]
     then
         # get created port 0 ephemeral port
         PORT=$(cat "$READY_FILE")
diff --git a/scripts/scp.test b/scripts/scp.test
index 20f9737e..b13751e3 100755
--- a/scripts/scp.test
+++ b/scripts/scp.test
@@ -25,13 +25,15 @@ fi
 create_port() {
     # each server gets its own wait budget, the count must not carry over
     counter=0
-    while [ ! -s "$ready_file" ] && [ "$counter" -lt 20 ]; do
+    while [ ! -s "$ready_file" ] && [ "$counter" -lt 100 ]; do
         echo -e "waiting for ready file..."
         sleep 0.1
         counter=$((counter+ 1))
     done
 
-    if test -e $ready_file; then
+    # -s, not -e: the echoserver creates the file empty and writes the
+    # port afterward, so -e can catch it mid-write and yield no port
+    if [ -s "$ready_file" ]; then
         echo -e "found ready file, starting client..."
 
         # get created port 0 ephemeral port
diff --git a/scripts/sftp.test b/scripts/sftp.test
index 3d5304cf..ac1a0000 100755
--- a/scripts/sftp.test
+++ b/scripts/sftp.test
@@ -35,7 +35,7 @@ create_port() {
     # counted per server start, so a slow first start cannot eat the wait
     # the later ones need
     counter=0
-    while [ ! -s "$ready_file" ] && [ "$counter" -lt 20 ]; do
+    while [ ! -s "$ready_file" ] && [ "$counter" -lt 100 ]; do
         echo "waiting for ready file..."
         sleep 0.1
         counter=$((counter+ 1))