diff --git a/zsnes/src/configure.in b/zsnes/src/configure.in
index 74cfcba1..2c8f3907 100644
--- a/zsnes/src/configure.in
+++ b/zsnes/src/configure.in
@@ -25,7 +25,7 @@ AC_CHECK_TOOL(NASMPATH,nasm,"no",$nasm_prefix:$PATH)
 if test x$NASMPATH = xno; then
 AC_MSG_ERROR(You need NASM installed to compile ZSNES)
 fi
-NFLAGS="$NFLAGS -w-orphan-labels"
+NFLAGS="$NFLAGS -O1 -w-orphan-labels"
 AC_PROG_INSTALL
 case "$target" in
 	*-*-linux*)
diff --git a/zsnes/src/makefile.dos b/zsnes/src/makefile.dos
index 22220ca5..2db3c0a5 100644
--- a/zsnes/src/makefile.dos
+++ b/zsnes/src/makefile.dos
@@ -64,7 +64,7 @@ LIBS=-lz -lm -lpng
 CFLAGS=-O3 -march=i586 -fno-rtti -fno-exceptions -ffast-math\
 -fomit-frame-pointer -fno-unroll-loops -Wall -Wno-unused -D__MSDOS__
 ASM=nasm
-ASMFLAGS=-f coff -D__MSDOS__
+ASMFLAGS=-O1 -f coff -D__MSDOS__
 CC=gcc
 PP=gpp
 
diff --git a/zsnes/src/makefile.win b/zsnes/src/makefile.win
index 77c51efd..c88bdb3d 100644
--- a/zsnes/src/makefile.win
+++ b/zsnes/src/makefile.win
@@ -69,7 +69,7 @@ OBJS=${CHIPSOBJ} ${CPUOBJ} ${WINOBJ} ${GUIOBJ} ${VIDEOBJ} ${ZIPOBJ} ${MAINOBJ} $
 LIBS=
 CFLAGS=/Ox /G6 /c /D__WIN32__
 ASM=nasm
-ASMFLAGS=-f win32 -D__WIN32__
+ASMFLAGS=-O1 -f win32 -D__WIN32__
 CC=cl
 
 .SUFFIXES: .c .cpp .asm