diff --git a/Libraries/LibGC/CMakeLists.txt b/Libraries/LibGC/CMakeLists.txt
index 7d93203ab703..805c7461146a 100644
--- a/Libraries/LibGC/CMakeLists.txt
+++ b/Libraries/LibGC/CMakeLists.txt
@@ -22,3 +22,9 @@ if (ENABLE_SWIFT)
     target_link_libraries(LibGC PRIVATE AK)
     add_swift_target_properties(LibGC LAGOM_LIBRARIES AK)
 endif()
+
+if (WIN32)
+    find_package(mman REQUIRED)
+    target_include_directories(LibGC PRIVATE ${MMAN_INCLUDE_DIR})
+    target_link_libraries(LibGC PRIVATE ${MMAN_LIBRARY})
+endif()