diff --git a/requirements-dev.txt b/requirements-dev.txt
index acd495b..1f6685d 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -163,7 +163,7 @@
     # via
     #   -r https://osm.etsi.org/gitweb/?p=osm/N2VC.git;a=blob_plain;f=requirements.txt;hb=paas
     #   pyrfc3339
-pyyaml==5.4.1
+pyyaml==5.3.1
     # via
     #   -r https://osm.etsi.org/gitweb/?p=osm/N2VC.git;a=blob_plain;f=requirements.txt;hb=paas
     #   -r https://osm.etsi.org/gitweb/?p=osm/common.git;a=blob_plain;f=requirements.txt;hb=paas
diff --git a/requirements.in b/requirements.in
index cc55f0d..abddaa5 100644
--- a/requirements.in
+++ b/requirements.in
@@ -34,6 +34,6 @@
 python-novaclient
 python-cinderclient==8.3.0
 pyvcloud
-pyyaml==5.4.1 # dependency comes from common
+pyyaml==5.3.1
 requests
 six
diff --git a/requirements.txt b/requirements.txt
index fe00489..6d20138 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -267,7 +267,7 @@
     # via tzlocal
 pyvcloud==23.0.4
     # via -r requirements.in
-pyyaml==5.4.1
+pyyaml==5.3.1
     # via
     #   -r requirements.in
     #   cliff