diff --git a/llvm/unittests/Passes/CMakeLists.txt b/llvm/unittests/Passes/CMakeLists.txt
--- a/llvm/unittests/Passes/CMakeLists.txt
+++ b/llvm/unittests/Passes/CMakeLists.txt
@@ -7,24 +7,30 @@
   add_definitions(-DLLVM_ENABLE_PLUGINS)
 endif()
 
-set(LLVM_LINK_COMPONENTS Support Passes Core)
-add_llvm_unittest(PluginsTests
-  PluginsTest.cpp
-  )
-export_executable_symbols(PluginsTests)
-target_link_libraries(PluginsTests PRIVATE LLVMTestingSupport)
+# The plugin expects to not link against the Support and Core libraries,
+# but expects them to exist in the process loading the plugin. This doesn't
+# work with DLLs on Windows (where a shared library can't have undefined
+# references), so just skip this testcase on Windows.
+if (NOT WIN32)
+  set(LLVM_LINK_COMPONENTS Support Passes Core)
+  add_llvm_unittest(PluginsTests
+    PluginsTest.cpp
+    )
+  export_executable_symbols(PluginsTests)
+  target_link_libraries(PluginsTests PRIVATE LLVMTestingSupport)
 
-set(LLVM_LINK_COMPONENTS)
-add_llvm_library(TestPlugin MODULE BUILDTREE_ONLY
-  TestPlugin.cpp
-  )
+  set(LLVM_LINK_COMPONENTS)
+  add_llvm_library(TestPlugin MODULE BUILDTREE_ONLY
+    TestPlugin.cpp
+    )
 
-# Put plugin next to the unit test executable.
-set_output_directory(TestPlugin
-  BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}
-  LIBRARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}
-  )
-set_target_properties(TestPlugin PROPERTIES FOLDER "Tests")
+  # Put plugin next to the unit test executable.
+  set_output_directory(TestPlugin
+    BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}
+    LIBRARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}
+    )
+  set_target_properties(TestPlugin PROPERTIES FOLDER "Tests")
 
-add_dependencies(TestPlugin intrinsics_gen)
-add_dependencies(PluginsTests TestPlugin)
+  add_dependencies(TestPlugin intrinsics_gen)
+  add_dependencies(PluginsTests TestPlugin)
+endif()