diff --git a/src/hdf5/HDF5IO.hpp b/src/hdf5/HDF5IO.hpp
index 94c42ebe..06295260 100644
--- a/src/hdf5/HDF5IO.hpp
+++ b/src/hdf5/HDF5IO.hpp
@@ -14,9 +14,7 @@ class DataType;
 class Exception;
 }  // namespace H5
 
-namespace AQNWB
-{
-namespace HDF5
+namespace AQNWB::HDF5
 {
 class HDF5RecordingData;  // declare here because gets used in HDF5IO class
 
@@ -277,5 +275,4 @@ class HDF5RecordingData : public BaseRecordingData
    */
   Status checkStatus(int status);
 };
-}  // namespace HDF5
-}  // namespace AQNWB
+}  // namespace AQNWB::HDF5
diff --git a/src/nwb/NWBFile.hpp b/src/nwb/NWBFile.hpp
index 1bf7bf34..cba9e50a 100644
--- a/src/nwb/NWBFile.hpp
+++ b/src/nwb/NWBFile.hpp
@@ -4,9 +4,7 @@
 
 #include "BaseIO.hpp"
 
-namespace AQNWB
-{
-namespace NWB
+namespace AQNWB::NWB
 {
 /**
  * @brief The NWBFile class provides an interface for setting up and managing
@@ -170,5 +168,4 @@ class NWBRecordingEngine
    */
   std::vector<int64_t> smpBuffer;
 };
-}  // namespace NWB
-}  // namespace AQNWB
+}  // namespace AQNWB::NWB
diff --git a/src/nwb/device/Device.hpp b/src/nwb/device/Device.hpp
index e8c230ee..74ae7062 100644
--- a/src/nwb/device/Device.hpp
+++ b/src/nwb/device/Device.hpp
@@ -5,9 +5,7 @@
 #include "BaseIO.hpp"
 #include "nwb/hdmf/base/Container.hpp"
 
-namespace AQNWB
-{
-namespace NWB
+namespace AQNWB::NWB
 {
 /**
  * @brief Metadata about a data acquisition device, e.g., recording system,
@@ -62,5 +60,4 @@ class Device : public Container
    */
   std::string manufacturer;
 };
-}  // namespace NWB
-}  // namespace AQNWB
+}  // namespace AQNWB::NWB
diff --git a/src/nwb/file/ElectrodeGroup.hpp b/src/nwb/file/ElectrodeGroup.hpp
index 210f6724..4f4c55ca 100644
--- a/src/nwb/file/ElectrodeGroup.hpp
+++ b/src/nwb/file/ElectrodeGroup.hpp
@@ -6,9 +6,7 @@
 #include "nwb/device/Device.hpp"
 #include "nwb/hdmf/base/Container.hpp"
 
-namespace AQNWB
-{
-namespace NWB
+namespace AQNWB::NWB
 {
 /**
  * @brief The ElectrodeGroup class represents a physical grouping of electrodes,
@@ -80,5 +78,4 @@ class ElectrodeGroup : public Container
    */
   Device device;
 };
-}  // namespace NWB
-}  // namespace AQNWB
+}  // namespace AQNWB::NWB
diff --git a/src/nwb/file/ElectrodeTable.hpp b/src/nwb/file/ElectrodeTable.hpp
index 39c2716d..40abdbbb 100644
--- a/src/nwb/file/ElectrodeTable.hpp
+++ b/src/nwb/file/ElectrodeTable.hpp
@@ -7,9 +7,7 @@
 #include "nwb/hdmf/table/ElementIdentifiers.hpp"
 #include "nwb/hdmf/table/VectorData.hpp"
 
-namespace AQNWB
-{
-namespace NWB
+namespace AQNWB::NWB
 {
 /**
  * @brief Represents a table containing electrode metadata.
@@ -117,5 +115,4 @@ class ElectrodeTable : public DynamicTable
    */
   std::string groupPath = "/general/extracellular_ephys/array1";
 };
-}  // namespace NWB
-}  // namespace AQNWB
+}  // namespace AQNWB::NWB
diff --git a/src/nwb/hdmf/base/Container.hpp b/src/nwb/hdmf/base/Container.hpp
index e35b7dbf..1d89c875 100644
--- a/src/nwb/hdmf/base/Container.hpp
+++ b/src/nwb/hdmf/base/Container.hpp
@@ -5,9 +5,7 @@
 
 #include "BaseIO.hpp"
 
-namespace AQNWB
-{
-namespace NWB
+namespace AQNWB::NWB
 {
 /**
  * @brief Abstract data type for a group storing collections of data and
@@ -50,5 +48,4 @@ class Container
    */
   std::shared_ptr<BaseIO> io;
 };
-}  // namespace NWB
-}  // namespace AQNWB
+}  // namespace AQNWB::NWB
diff --git a/src/nwb/hdmf/base/Data.hpp b/src/nwb/hdmf/base/Data.hpp
index 32bdb0ca..ef146485 100644
--- a/src/nwb/hdmf/base/Data.hpp
+++ b/src/nwb/hdmf/base/Data.hpp
@@ -4,9 +4,7 @@
 
 #include "BaseIO.hpp"
 
-namespace AQNWB
-{
-namespace NWB
+namespace AQNWB::NWB
 {
 /**
  * @brief An abstract data type for a dataset.
@@ -29,5 +27,4 @@ class Data
    */
   std::unique_ptr<BaseRecordingData> dataset;
 };
-}  // namespace NWB
-}  // namespace AQNWB
+}  // namespace AQNWB::NWB
diff --git a/src/nwb/hdmf/table/DynamicTable.hpp b/src/nwb/hdmf/table/DynamicTable.hpp
index 07f804b2..0e9f6cf7 100644
--- a/src/nwb/hdmf/table/DynamicTable.hpp
+++ b/src/nwb/hdmf/table/DynamicTable.hpp
@@ -7,9 +7,7 @@
 #include "nwb/hdmf/table/ElementIdentifiers.hpp"
 #include "nwb/hdmf/table/VectorData.hpp"
 
-namespace AQNWB
-{
-namespace NWB
+namespace AQNWB::NWB
 {
 /**
  * @brief Represents a group containing multiple datasets that are aligned on
@@ -96,5 +94,4 @@ class DynamicTable : public Container
    */
   std::vector<std::string> colNames;
 };
-}  // namespace NWB
-}  // namespace AQNWB
+}  // namespace AQNWB::NWB
diff --git a/src/nwb/hdmf/table/ElementIdentifiers.hpp b/src/nwb/hdmf/table/ElementIdentifiers.hpp
index 0af32db3..813f472e 100644
--- a/src/nwb/hdmf/table/ElementIdentifiers.hpp
+++ b/src/nwb/hdmf/table/ElementIdentifiers.hpp
@@ -2,9 +2,7 @@
 
 #include "nwb/hdmf/base/Data.hpp"
 
-namespace AQNWB
-{
-namespace NWB
+namespace AQNWB::NWB
 {
 /**
  * @brief A list of unique identifiers for values within a dataset, e.g. rows of
@@ -13,5 +11,4 @@ namespace NWB
 class ElementIdentifiers : public Data
 {
 };
-}  // namespace NWB
-}  // namespace AQNWB
+}  // namespace AQNWB::NWB
diff --git a/src/nwb/hdmf/table/VectorData.hpp b/src/nwb/hdmf/table/VectorData.hpp
index 0e574c81..7ee93f09 100644
--- a/src/nwb/hdmf/table/VectorData.hpp
+++ b/src/nwb/hdmf/table/VectorData.hpp
@@ -4,9 +4,7 @@
 
 #include "nwb/hdmf/base/Data.hpp"
 
-namespace AQNWB
-{
-namespace NWB
+namespace AQNWB::NWB
 {
 /**
  * @brief An n-dimensional dataset representing a column of a DynamicTable.
@@ -26,5 +24,4 @@ class VectorData : public Data
    */
   std::string description;
 };
-}  // namespace NWB
-}  // namespace AQNWB
+}  // namespace AQNWB::NWB