diff --git a/src/nwb/ecephys/ElectricalSeries.cpp b/src/nwb/ecephys/ElectricalSeries.cpp
index f0c690f1..14ce6ca4 100644
--- a/src/nwb/ecephys/ElectricalSeries.cpp
+++ b/src/nwb/ecephys/ElectricalSeries.cpp
@@ -54,7 +54,7 @@ void ElectricalSeries::initialize(const IO::BaseDataType& dataType,
                              getPath() + "/channel_conversion"));
   channelConversion->writeDataBlock(
       std::vector<SizeType>(1, channelVector.size()),
-      BaseDataType::F32,
+      IO::BaseDataType::F32,
       &channelConversions[0]);
   io->createCommonNWBAttributes(getPath() + "/channel_conversion",
                                 "hdmf-common",