diff --git a/Makefile b/Makefile
index 58f6ba6..1e80766 100644
--- a/Makefile
+++ b/Makefile
@@ -108,8 +108,8 @@ EMCCFLAGS_WASM += -s TOTAL_STACK=65536 -s TOTAL_MEMORY=262144
 
 EMCCFLAGS_ASMJS += -s WASM=0
 
-EMCC.c = $(EMCC) $(CFLAGS) $(CPPFLAGS) -c
-EMCC.cc = $(EMCC) $(CXXFLAGS) $(CPPFLAGS) -c
+EMCC.c = $(EMCC) $(CFLAGS) $(CPPFLAGS) -c -DNDEBUG
+EMCC.cc = $(EMCC) $(CXXFLAGS) $(CPPFLAGS) -c -DNDEBUG
 EMCC_LINK = $(EMCC) $(LDFLAGS) $(EMCCFLAGS)
 
 AFL_CC = afl-clang-fast