diff --git a/check_iperf3.sh b/check_iperf3.sh
index ea19fc3..e3b116b 100755
--- a/check_iperf3.sh
+++ b/check_iperf3.sh
@@ -90,13 +90,13 @@ done
 
 if ! command -v iperf3 &>/dev/null; then
   echo "UNKNOWN - iperf3 not found! Please install iperf3"
-  exit -1
+  exit 3
 fi
 
 # Check if required arguments are provided
 if [[ -z "$SERVER" ]] || [[ -z "$WARNING_LEVEL" ]] || [[ -z "$CRITICAL_LEVEL" ]]; then
   echo "Usage: $0 --server SERVER --warning WARNING_LEVEL --critical CRITICAL_LEVEL [--rsa-public-key RSA_PUBLIC_KEY] [--username USERNAME] [--password PASSWORD]"
-  exit -1
+  exit 3
 fi
 
 # Set IPERF3_PASSWORD environment variable
@@ -112,14 +112,14 @@ for ((i = 1; i <= RETRY; i++)); do
 
   # Check if iperf3 command failed
   if [[ $? -ne 0 ]]; then
-    if [[ $OUTPUT == *"the server is busy running a test. try again later"* ]]; then
+    if [[ $OUTPUT == *"the server is busy running a test"* ]]; then
       if [[ $i -lt $RETRY ]]; then
-        sleep 30
+        sleep 60
         continue
       fi
     fi
     echo -e "UNKNOWN - iperf3 command failed: $OUTPUT\n"
-    exit -1
+    exit 3
   else
     break
   fi