diff --git a/Makefile b/Makefile
index 4df9a369..1d367bf1 100644
--- a/Makefile
+++ b/Makefile
@@ -31,6 +31,10 @@ else
   DOCONFIG_FILENAME_DEF = DoConfig_debug$(EXE_EXTENSION)
 endif
 
+ifeq ($(LTO), 1)
+  ALL_CXXFLAGS += -flto
+endif
+
 ifeq ($(JAPANESE), 1)
   DATA_DIRECTORY = $(ASSETS_DIRECTORY)/data_jp
 
diff --git a/README.md b/README.md
index 8200bf5e..17886890 100644
--- a/README.md
+++ b/README.md
@@ -93,6 +93,7 @@ Name | Function
 --------|--------
 `RELEASE=1` | Compile a release build (optimised, stripped, etc.)
 `STATIC=1` | Produce a statically-linked executable (good for Windows builds, so you don't need to bundle DLL files)
+`LTO=1` | Enable link-time optimisation
 `JAPANESE=1` | Enable the Japanese-language build (instead of the unofficial Aeon Genesis English translation)
 `FIX_BUGS=1` | Fix various bugs in the game
 `WINDOWS=1` | Build for Windows