diff --git a/lib/ArchestrA.CloudHistorian.Contract.dll b/lib/ArchestrA.CloudHistorian.Contract.dll
index f96d525..2ea9ecc 100644
Binary files a/lib/ArchestrA.CloudHistorian.Contract.dll and b/lib/ArchestrA.CloudHistorian.Contract.dll differ
diff --git a/lib/Historian.CBE.dll b/lib/Historian.CBE.dll
index aaedc65..0dc1513 100644
Binary files a/lib/Historian.CBE.dll and b/lib/Historian.CBE.dll differ
diff --git a/lib/Historian.DPAPI.dll b/lib/Historian.DPAPI.dll
index 50f8d59..5e4777f 100644
Binary files a/lib/Historian.DPAPI.dll and b/lib/Historian.DPAPI.dll differ
diff --git a/lib/aahClient.dll b/lib/aahClient.dll
index 0543572..3b61fe1 100644
Binary files a/lib/aahClient.dll and b/lib/aahClient.dll differ
diff --git a/lib/aahClientCommon.dll b/lib/aahClientCommon.dll
index c36152b..567f6dd 100644
Binary files a/lib/aahClientCommon.dll and b/lib/aahClientCommon.dll differ
diff --git a/lib/aahClientManaged.dll b/lib/aahClientManaged.dll
index 2834fca..12337e9 100644
Binary files a/lib/aahClientManaged.dll and b/lib/aahClientManaged.dll differ
diff --git a/src/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.csproj b/src/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.csproj
index 24c3ca8..673bfe1 100644
--- a/src/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.csproj
+++ b/src/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.csproj
@@ -3,10 +3,13 @@
     <PropertyGroup>
         <OutputType>Exe</OutputType>
         <TargetFramework>net48</TargetFramework>
-        <!-- x86 to match the in-process bitness expectations of the Wonderware Historian SDK
-             that PR 3.2 lifted in. Mirrors Driver.Galaxy.Host's bitness for consistency. -->
-        <PlatformTarget>x86</PlatformTarget>
-        <Prefer32Bit>true</Prefer32Bit>
+        <!-- x64 — AVEVA Historian 2020 ships an x64 build of aahClientManaged + the native
+             aahClient.dll under the Historian install's x64\ subfolder. The other three
+             SDK assemblies (Historian.CBE / DPAPI / ArchestrA.CloudHistorian.Contract) are
+             pure-managed AnyCPU and load fine in either bitness. The earlier x86 default
+             was inherited from v1's Galaxy.Host bitness (MXAccess COM, retired in PR 7.2)
+             and didn't reflect any constraint of the Historian SDK itself. -->
+        <PlatformTarget>x64</PlatformTarget>
         <Nullable>enable</Nullable>
         <LangVersion>latest</LangVersion>
         <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
diff --git a/tests/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Tests/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Tests.csproj b/tests/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Tests/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Tests.csproj
index 2d80209..cd0839d 100644
--- a/tests/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Tests/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Tests.csproj
+++ b/tests/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Tests/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Tests.csproj
@@ -2,8 +2,7 @@
 
     <PropertyGroup>
         <TargetFramework>net48</TargetFramework>
-        <PlatformTarget>x86</PlatformTarget>
-        <Prefer32Bit>true</Prefer32Bit>
+        <PlatformTarget>x64</PlatformTarget>
         <Nullable>enable</Nullable>
         <LangVersion>latest</LangVersion>
         <IsPackable>false</IsPackable>