diff --git a/indra/cmake/00-Common.cmake b/indra/cmake/00-Common.cmake
index 03da30649a1c87033bdb40e6f326203bd3f0f326..865c057e33f064cebafaa62bd29c41bc3406ad5c 100644
--- a/indra/cmake/00-Common.cmake
+++ b/indra/cmake/00-Common.cmake
@@ -60,7 +60,10 @@ if (WINDOWS)
   # http://www.cmake.org/pipermail/cmake/2009-September/032143.html
   string(REPLACE "/Zm1000" " " CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
 
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP")
+  # Without PreferredToolArchitecture=x64, as of 2020-06-26 the 32-bit
+  # compiler on our TeamCity build hosts has started running out of virtual
+  # memory for the precompiled header file.
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP /p:PreferredToolArchitecture=x64")
 
   set(CMAKE_CXX_FLAGS_RELWITHDEBINFO 
       "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} /Zo"