diff --git a/CHANGELOG.md b/CHANGELOG.md
index 89ce6fa..706b36a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- Remove parallel requests improvement, because it's buggy in some situations...
+
 ## [1.3.0-alpha] - 2021-09-14
 ### Changed
 - **Breaking Change**: [HTTPie](https://httpie.io/) is replaced by [cURL](https://curl.se), for smaller Docker images, faster execution and to be more portable
diff --git a/psu b/psu
index 51b25bc..08aed22 100755
--- a/psu
+++ b/psu
@@ -185,7 +185,7 @@ main() {
       # or desired state == 'shutdown' and state == 'complete'
       # Tasks should not have one of these states:
       # 'failed', 'orphaned', 'remove'
-      timeout "$TIMEOUT" bash -c "until (export PORTAINER_SERVICE_NAME=$PORTAINER_SERVICE_NAME && psu --action=tasks:healthy --quiet --debug=false --verbose=false) >/dev/null 2>&1; do echo -n \$(if [ \"\$VERBOSE_MODE\" == \"true\" ]; then echo -n .; fi) && sleep 1; done;"
+      timeout "$TIMEOUT" bash -c "until (export HTTPIE_VERIFY_SSL=$HTTPIE_VERIFY_SSL && export PORTAINER_SERVICE_NAME=$PORTAINER_SERVICE_NAME && export PORTAINER_AUTH_TOKEN=$PORTAINER_AUTH_TOKEN && export PORTAINER_URL=$PORTAINER_URL && export PORTAINER_STACK_NAME=$PORTAINER_STACK_NAME && export DEBUG_MODE=false && export VERBOSE_MODE=false && psu --action tasks:healthy --quiet) >/dev/null 2>&1; do echo -n \$(if [ \"$VERBOSE_MODE\" == \"true\" ]; then echo -n .; fi) && sleep 1; done;"
       status=$?
 
       if $(exit $status); then
@@ -208,14 +208,18 @@ main() {
       echo_debug "Tasks action response -> $(echo $tasks | jq -C .)"
     else
       echo_verbose "List $scope tasks of stack '$PORTAINER_STACK_NAME'..."
-      # Boost performance with parallel requests
-      # See: https://stackoverflow.com/questions/8634109/parallel-download-using-curl-command-line-utility#comment51239188_24276040
-      local tasks_action
-      tasks_action="$(if [ "$scope" == "healthy" ]; then echo "tasks:healthy"; else echo "tasks"; fi)"
-      local new_tasks
-      new_tasks=$(psu --action=services --quiet --debug=false --verbose=false | sed "s/^${PORTAINER_STACK_NAME}_\(.*\)$/\1/" | \
-          xargs -I "{}" -P 10 -- psu --action="$tasks_action" --service={} --quiet=false --debug=false --verbose=false)
-      tasks="$(echo "$new_tasks" | jq -sjc 'add | unique_by(.ID)')"
+      local services
+      services="$(timeout "$TIMEOUT" bash -c "until (export HTTPIE_VERIFY_SSL=$HTTPIE_VERIFY_SSL && export PORTAINER_AUTH_TOKEN=$PORTAINER_AUTH_TOKEN && export PORTAINER_URL=$PORTAINER_URL && export PORTAINER_STACK_NAME=$PORTAINER_STACK_NAME && export DEBUG_MODE=false && export VERBOSE_MODE=false && echo \"\$(psu --action services --quiet)\"); do sleep 1; done;")"
+      for service in $services; do
+        export PORTAINER_SERVICE_NAME=${service#"${PORTAINER_STACK_NAME}_"}
+        local new_tasks
+        new_tasks=$(if [ "$scope" == "healthy" ]; then tasks_healthy; else tasks; fi)
+        if [ -z "$new_tasks" ] || [ "$new_tasks" == "[]" ]; then
+          echo_verbose "Error: $scope tasks aren't running correctly for the stack \"$PORTAINER_STACK_NAME\""
+          exit 1;
+        fi
+        tasks="$(echo "${tasks}${new_tasks}" | jq -sjc 'add | unique_by(.ID)')"
+      done
       echo_debug "Tasks action response -> $(echo $tasks | jq -C .)"
     fi