diff --git a/runtime/flang/CMakeLists.txt b/runtime/flang/CMakeLists.txt
index 345cc88c2ad..a6a4403fa66 100644
--- a/runtime/flang/CMakeLists.txt
+++ b/runtime/flang/CMakeLists.txt
@@ -579,6 +579,9 @@ add_dependencies(flang_shared
 if (NOT MSVC)
   target_compile_options(flang_static PRIVATE -fPIC)
   target_compile_options(flang_shared PRIVATE -fPIC)
+else()
+  set_target_properties(flang_static PROPERTIES LINKER_LANGUAGE CXX)
+  set_target_properties(flang_shared PROPERTIES LINKER_LANGUAGE CXX)
 endif()
 
 target_compile_options(flang_static PUBLIC $<$<COMPILE_LANGUAGE:Fortran>:-Mreentrant>)
diff --git a/runtime/flangrti/CMakeLists.txt b/runtime/flangrti/CMakeLists.txt
index 82cbe1bfb6b..2dc0cda32f1 100644
--- a/runtime/flangrti/CMakeLists.txt
+++ b/runtime/flangrti/CMakeLists.txt
@@ -234,6 +234,8 @@ set_target_properties(flangrti_shared flangrti_static
 if (NOT MSVC)
   target_compile_options(flangrti_static PRIVATE -fPIC)
   target_compile_options(flangrti_shared PRIVATE -fPIC)
+else()
+  set_target_properties(flangrti_shared PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS TRUE)
 endif()
 
 target_compile_options(flangrti_static PUBLIC $<$<COMPILE_LANGUAGE:Fortran>:-Mreentrant>)