diff --git a/Makefile b/Makefile
index 6007a46..b245ace 100644
--- a/Makefile
+++ b/Makefile
@@ -104,7 +104,7 @@ EMCCFLAGS = --closure 1 --memory-init-file 0 -s NO_FILESYSTEM=1 -s INVOKE_RUN=0
 # (This can't be changed by the app with wasm since it's baked into the wasm).
 # (emscripten also mandates at least 16MB of memory for asm.js now, so
 # we don't use this for the legacy build.)
-EMCCFLAGS_WASM += -s TOTAL_STACK=65536 -s TOTAL_MEMORY=262144
+EMCCFLAGS_WASM += -s TOTAL_STACK=65536 -s TOTAL_MEMORY=262144 -s ALLOW_MEMORY_GROWTH
 
 EMCCFLAGS_ASMJS += -s WASM=0