diff --git a/devices/devices/apsct.py b/devices/devices/apsct.py
index debc132d4abff1f1c66a0a276104c679b463831b..b235ced3f2a5a2b9d44f544caf847d5366acc2e2 100644
--- a/devices/devices/apsct.py
+++ b/devices/devices/apsct.py
@@ -65,7 +65,7 @@ class APSCT(opcua_device):
     APSCT_PWR_PLL_200MHz_on_R    = attribute_wrapper(comms_annotation=["APSCT_PWR_PLL_200MHz_on_R" ],datatype=numpy.bool_  )
     APSCT_PWR_PPSDIST_3V3_R      = attribute_wrapper(comms_annotation=["APSCT_PWR_PPSDIST_3V3_R"   ],datatype=numpy.float64)
     APSCT_temperature_R          = attribute_wrapper(comms_annotation=["APSCT_temperature_R"       ],datatype=numpy.float64)
-    APSCT_version_R              = attribute_wrapper(comms_annotation=["APSCT_version_R"           ],datatype=str          )
+    APSCT_version_R              = attribute_wrapper(comms_annotation=["APSCT_version_R"           ],datatype=numpy.str    )
 
     # --------
     # overloaded functions
diff --git a/devices/devices/apspu.py b/devices/devices/apspu.py
index 4c3d04b201dcfd85f9232e38e26f529a8c9ec0f2..cec9e56364a7c78d8938d0fb9241a840d1e0f95e 100644
--- a/devices/devices/apspu.py
+++ b/devices/devices/apspu.py
@@ -58,7 +58,7 @@ class APSPU(opcua_device):
     APSPU_RCU2D_IOUT_R           = attribute_wrapper(comms_annotation=["APSPU_RCU2D_IOUT_R"        ],datatype=numpy.float64)
     APSPU_RCU2D_TEMP_R           = attribute_wrapper(comms_annotation=["APSPU_RCU2D_TEMP_R"        ],datatype=numpy.float64)
     APSPU_RCU2D_VOUT_R           = attribute_wrapper(comms_annotation=["APSPU_RCU2D_VOUT_R"        ],datatype=numpy.float64)
-    APSPU_version_R              = attribute_wrapper(comms_annotation=["APSPU_version_R"           ],datatype=str          )
+    APSPU_version_R              = attribute_wrapper(comms_annotation=["APSPU_version_R"           ],datatype=numpy.str    )
 
     # --------
     # overloaded functions
diff --git a/devices/devices/recv.py b/devices/devices/recv.py
index f2f15255c98a537e53a6732ee30730e26db67d12..a3ae458bd6a001d64a27439a011ff8db0f1cc8d3 100644
--- a/devices/devices/recv.py
+++ b/devices/devices/recv.py
@@ -99,7 +99,7 @@ class RECV(opcua_device):
     RCU_PWR_DIGITAL_on_R         = attribute_wrapper(comms_annotation=["RCU_PWR_DIGITAL_on_R"      ],datatype=numpy.bool_  , dims=(32,))
     RCU_PWR_good_R               = attribute_wrapper(comms_annotation=["RCU_PWR_good_R"            ],datatype=numpy.bool_  , dims=(32,))
     RCU_temperature_R            = attribute_wrapper(comms_annotation=["RCU_temperature_R"         ],datatype=numpy.float64, dims=(32,))
-    RCU_version_R                = attribute_wrapper(comms_annotation=["RCU_version_R"             ],datatype=str          , dims=(32,))
+    RCU_version_R                = attribute_wrapper(comms_annotation=["RCU_version_R"             ],datatype=numpy.str    , dims=(32,))
     RECVTR_translator_busy_R     = attribute_wrapper(comms_annotation=["RECVTR_translator_busy_R"  ],datatype=numpy.bool_  )
 
     # --------
diff --git a/devices/devices/unb2.py b/devices/devices/unb2.py
index eeb42b55906e8a9f39057972ae65fefba9f3fda1..bad1b1a324c9c838960d07cdfeb804b2789bbac6 100644
--- a/devices/devices/unb2.py
+++ b/devices/devices/unb2.py
@@ -69,7 +69,7 @@ class UNB2(opcua_device):
     UNB2_DC_DC_48V_12V_TEMP_R    = attribute_wrapper(comms_annotation=["UNB2_DC_DC_48V_12V_TEMP_R" ],datatype=numpy.float64, dims=(2,))
     UNB2_DC_DC_48V_12V_VIN_R     = attribute_wrapper(comms_annotation=["UNB2_DC_DC_48V_12V_VIN_R"  ],datatype=numpy.float64, dims=(2,))
     UNB2_DC_DC_48V_12V_VOUT_R    = attribute_wrapper(comms_annotation=["UNB2_DC_DC_48V_12V_VOUT_R" ],datatype=numpy.float64, dims=(2,))
-    UNB2_EEPROM_Serial_Number_R  = attribute_wrapper(comms_annotation=["UNB2_EEPROM_Serial_Number_R"],datatype=str          , dims=(2,))
+    UNB2_EEPROM_Serial_Number_R  = attribute_wrapper(comms_annotation=["UNB2_EEPROM_Serial_Number_R"],datatype=numpy.str    , dims=(2,))
     UNB2_EEPROM_Unique_ID_R      = attribute_wrapper(comms_annotation=["UNB2_EEPROM_Unique_ID_R"   ],datatype=numpy.int64  , dims=(2,))
     UNB2_FPGA_DDR4_SLOT_TEMP_R   = attribute_wrapper(comms_annotation=["UNB2_FPGA_DDR4_SLOT_TEMP_R"],datatype=numpy.float64, dims=(16,))
     UNB2_FPGA_POL_CORE_IOUT_R    = attribute_wrapper(comms_annotation=["UNB2_FPGA_POL_CORE_IOUT_R" ],datatype=numpy.float64, dims=(8,))