diff --git a/README.md b/README.md
index 05414c6c..490ba8fe 100644
--- a/README.md
+++ b/README.md
@@ -277,6 +277,7 @@ the Wine prefix. Removing the option will revert to the previous behavior.
 | <tt>noxim</tt>        | <tt>PROTON_NO_XIM</tt>         | Enabled by default. Do not attempt to use XIM (X Input Methods) support. XIM support is known to cause crashes with libx11 older than version 1.7. |
 | <tt>nativevulkanloader</tt> |                          | Use the Vulkan loader shipped with the game instead of Proton's built-in Vulkan loader. This breaks VR support, but is required by a few games. |
 | <tt>forcelgadd</tt>   | <tt>PROTON_FORCE_LARGE_ADDRESS_AWARE</tt> | Force Wine to enable the LARGE_ADDRESS_AWARE flag for all executables. Enabled by default. |
+| <tt>heapdelayfree</tt>| <tt>PROTON_HEAP_DELAY_FREE</tt>| Delay freeing some memory, to work around application use-after-free bugs. |
 | <tt>gamedrive</tt>    | <tt>PROTON_SET_GAME_DRIVE</tt> | Create an S: drive which points to the Steam Library which contains the game. |
 | <tt>noforcelgadd</tt> |                                | Disable forcelgadd. If both this and `forcelgadd` are set, enabled wins. |
 | <tt>oldglstr</tt>     | <tt>PROTON_OLD_GL_STRING</tt>  | Set some driver overrides to limit the length of the GL extension string, for old games that crash on very long extension strings. |
diff --git a/proton b/proton
index 67f7ac72..0084a547 100755
--- a/proton
+++ b/proton
@@ -730,6 +730,7 @@ class Session:
         self.check_environment("PROTON_HIDE_NVIDIA_GPU", "hidenvgpu")
         self.check_environment("PROTON_SET_GAME_DRIVE", "gamedrive")
         self.check_environment("PROTON_NO_XIM", "noxim")
+        self.check_environment("PROTON_HEAP_DELAY_FREE", "heapdelayfree")
 
         if "noesync" in self.compat_config:
             self.env.pop("WINEESYNC", "")
@@ -756,6 +757,9 @@ class Session:
         if "forcelgadd" in self.compat_config:
             self.env["WINE_LARGE_ADDRESS_AWARE"] = "1"
 
+        if "heapdelayfree" in self.compat_config:
+            self.env["WINE_HEAP_DELAY_FREE"] = "1"
+
         if "vkd3dbindlesstb" in self.compat_config:
             append_to_env_str(self.env, "VKD3D_CONFIG", "force_bindless_texel_buffer", ",")