diff --git a/build/Version.props b/build/Version.props
index 8dd9afbf2d..3c1098f7b7 100644
--- a/build/Version.props
+++ b/build/Version.props
@@ -8,7 +8,7 @@
     <TgsApiVersion>9.9.0</TgsApiVersion>
     <TgsApiLibraryVersion>10.3.0</TgsApiLibraryVersion>
     <TgsClientVersion>11.3.0</TgsClientVersion>
-    <TgsDmapiVersion>6.4.1</TgsDmapiVersion>
+    <TgsDmapiVersion>6.4.2</TgsDmapiVersion>
     <TgsInteropVersion>5.6.0</TgsInteropVersion>
     <TgsHostWatchdogVersion>1.2.1</TgsHostWatchdogVersion>
     <TgsContainerScriptVersion>1.2.1</TgsContainerScriptVersion>
diff --git a/src/DMAPI/tgs.dm b/src/DMAPI/tgs.dm
index 42787bc889..c8ef71112b 100644
--- a/src/DMAPI/tgs.dm
+++ b/src/DMAPI/tgs.dm
@@ -1,6 +1,6 @@
 // tgstation-server DMAPI
 
-#define TGS_DMAPI_VERSION "6.4.1"
+#define TGS_DMAPI_VERSION "6.4.2"
 
 // All functions and datums outside this document are subject to change with any version and should not be relied on.
 
diff --git a/src/DMAPI/tgs/v5/undefs.dm b/src/DMAPI/tgs/v5/undefs.dm
index 2e3b7ae771..e3455b69d1 100644
--- a/src/DMAPI/tgs/v5/undefs.dm
+++ b/src/DMAPI/tgs/v5/undefs.dm
@@ -14,6 +14,7 @@
 #undef DMAPI5_BRIDGE_COMMAND_REBOOT
 #undef DMAPI5_BRIDGE_COMMAND_KILL
 #undef DMAPI5_BRIDGE_COMMAND_CHAT_SEND
+#undef DMAPI5_BRIDGE_COMMAND_CHUNK
 
 #undef DMAPI5_PARAMETER_ACCESS_IDENTIFIER
 #undef DMAPI5_PARAMETER_CUSTOM_COMMANDS