diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4e509e01..ed157136 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -318,4 +318,14 @@ if (MSVC)
   set(CMAKE_SHARED_LINKER_FLAGS_RELEASE "/incremental:no")
   set(CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO "/incremental:no /debug")
   set(CMAKE_SHARED_LINKER_FLAGS_MINSIZEREL "/incremental:no")
+
+  # Older MSVC versions don't support building in parallel.
+  # Force non-parallel builds of isle and lego1 by putting them in a pool with 1 available job.
+  if(CMAKE_CXX_COMPILER_ID VERSION_LESS 12)
+    set_property(GLOBAL PROPERTY JOB_POOLS "msvc_lego=1;msvc_lego1=1")
+    set_property(TARGET isle PROPERTY JOB_POOL_COMPILE msvc_lego)
+    set_property(TARGET isle PROPERTY JOB_POOL_LINK msvc_lego)
+    set_property(TARGET lego1 PROPERTY JOB_POOL_COMPILE msvc_lego1)
+    set_property(TARGET lego1 PROPERTY JOB_POOL_LINK msvc_lego1)
+  endif()
 endif()