diff --git a/Makefile b/Makefile
index 1a17bb857..ef838624a 100644
--- a/Makefile
+++ b/Makefile
@@ -164,7 +164,7 @@ else ifeq ($(CONFIG),emcc)
 CXX = emcc
 LD = emcc
 CXXFLAGS := -std=c++11 $(filter-out -fPIC -ggdb,$(CXXFLAGS))
-ABCMKARGS += ARCHFLAGS="-DABC_USE_STDINT_H"
+ABCMKARGS += ARCHFLAGS="-DABC_USE_STDINT_H -DABC_MEMALIGN=8"
 EMCCFLAGS := -Os -Wno-warn-absolute-paths
 EMCCFLAGS += --memory-init-file 0 --embed-file share -s NO_EXIT_RUNTIME=1
 EMCCFLAGS += -s EXPORTED_FUNCTIONS="['_main','_run','_prompt','_errmsg']"