diff --git a/logger.sh b/logger.sh
index 466db8d..3cbe0d2 100644
--- a/logger.sh
+++ b/logger.sh
@@ -91,8 +91,8 @@ writeJsonLog() {
       --arg level "$(standardizeLogLevels "$2")" \
       --arg status "$(uppercase "$3")" \
       --arg message "$1" \
-      --arg operation "${4:UNSPECIFIED}" \
-      --arg code "${5:999}" \
+      --arg operation "${4:-UNSPECIFIED}" \
+      --arg code "${5:-999}" \
       '{"timestamp":$timestamp, "hostname":$hostname, "programName":$pName, "pid":$pid, "level":$level, "status":$status, "message":$message, "operation":$operation, "code":$code}' \
   )"
 
@@ -115,8 +115,8 @@ SYSLOG_PID="$$"
 PRIORITY="$(translateLogLevelsToJournalD "$2")"
 STATUS="$(uppercase "$3")"
 MESSAGE="$1"
-OPERATION="${4:UNSPECIFIED}"
-ERRNO="${5:999}"
+OPERATION="${4:-UNSPECIFIED}"
+ERRNO="${5:-999}"
 end
 
   return