diff --git a/requirements.txt b/requirements.txt
index 29f58b5168e9326c976e38372afedc3d0d4c4d77..4a3f79dd0651dd1e85c8e72f74264a7f5a6cecde 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,8 +5,7 @@ attrs==19.3.0
 chardet==3.0.4
 colorama==0.4.3
 cpplint==1.5.4
-crc==0.4.1
-crcmod==1.7
+crcmod>=1.7
 docopt==0.6.2
 future==0.18.2
 idna==2.10
@@ -15,12 +14,11 @@ isort==5.4.2
 lazy-object-proxy==1.5.1
 mccabe==0.6.1
 multidict==4.7.6
-pylint==2.5.3
-PyQt5==5.15.0
-PyQt5-sip==12.8.0
-pyserial==3.4
+pylint>=2.5.3
+PyQt5>=5.15.0
+PyQt5-sip>=12.8.0
+pyserial>=3.4
 PyYAML==5.3.1
-serial==0.0.97
 six==1.15.0
 toml==0.10.1
 typing-extensions==3.7.4.2
diff --git a/tm/obsw_pus_tm_base.py b/tm/obsw_pus_tm_base.py
index 9eeadf7b806174793b6f1cb2340a5230fd4d1421..8be751a5f3f9d87704b1c2cd26c2424961a6388b 100644
--- a/tm/obsw_pus_tm_base.py
+++ b/tm/obsw_pus_tm_base.py
@@ -44,6 +44,7 @@ class PusTelemetry:
     PUS_HEADER_SIZE = 6
     CDS_SHORT_SIZE = 7
     PUS_TIMESTAMP_SIZE = CDS_SHORT_SIZE
+
     def __init__(self, raw_telemetry: bytearray = bytearray()):
         if raw_telemetry == bytearray():
             return