diff --git a/Dockerfile b/Dockerfile
index 7b8432d..b77c009 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,12 +4,13 @@ FROM ubuntu:20.04
 RUN apt-get update --yes && \
     apt-get upgrade --yes && \
     apt-get install --yes \
-    build-essential && \
+    build-essential autoconf && \
     rm -rf /var/lib/apt/lists/* && \
     rm -Rf /usr/share/doc && \
     rm -Rf /usr/share/man && \
     apt-get autoremove -y
 
+RUN apt-get update --yes && apt-get install --yes libtool
 
 ADD . /crfpp
 WORKDIR /crfpp
diff --git a/Makefile b/Makefile
index 91b2948..ec7b11a 100644
--- a/Makefile
+++ b/Makefile
@@ -139,12 +139,12 @@ distuninstallcheck_listfiles = find . -type f -print
 am__distuninstallcheck_listfiles = $(distuninstallcheck_listfiles) \
   | sed 's|^\./|$(prefix)/|' | grep -v '$(infodir)/dir$$'
 distcleancheck_listfiles = find . -type f -print
-ACLOCAL = ${SHELL} /Users/taku/proj/crfpp/missing --run aclocal-1.11
+ACLOCAL = ${SHELL} /crfpp/missing --run aclocal-1.11
 AMTAR = $${TAR-tar}
 AR = ar
-AUTOCONF = ${SHELL} /Users/taku/proj/crfpp/missing --run autoconf
-AUTOHEADER = ${SHELL} /Users/taku/proj/crfpp/missing --run autoheader
-AUTOMAKE = ${SHELL} /Users/taku/proj/crfpp/missing --run automake-1.11
+AUTOCONF = ${SHELL} /crfpp/missing --run autoconf
+AUTOHEADER = ${SHELL} /crfpp/missing --run autoheader
+AUTOMAKE = ${SHELL} /crfpp/missing --run automake-1.11
 AWK = awk
 CC = gcc
 CCDEPMODE = depmode=gcc3
@@ -181,7 +181,7 @@ LIBTOOL = $(SHELL) $(top_builddir)/libtool
 LIPO = lipo
 LN_S = ln -s
 LTLIBOBJS = 
-MAKEINFO = ${SHELL} /Users/taku/proj/crfpp/missing --run makeinfo
+MAKEINFO = ${SHELL} /crfpp/missing --run makeinfo
 MANIFEST_TOOL = :
 MKDIR_P = /usr/local/bin/gmkdir -p
 NM = /usr/bin/nm
@@ -201,13 +201,13 @@ PATH_SEPARATOR = :
 RANLIB = ranlib
 SED = /usr/bin/sed
 SET_MAKE = 
-SHELL = /bin/sh
+SHELL = /bin/bash
 STRIP = strip
 VERSION = 0.59
-abs_builddir = /Users/taku/proj/crfpp
-abs_srcdir = /Users/taku/proj/crfpp
-abs_top_builddir = /Users/taku/proj/crfpp
-abs_top_srcdir = /Users/taku/proj/crfpp
+abs_builddir = /crfpp
+abs_srcdir = /crfpp
+abs_top_builddir = /crfpp
+abs_top_srcdir = /crfpp
 ac_ct_AR = ar
 ac_ct_CC = gcc
 ac_ct_CXX = g++
@@ -237,7 +237,7 @@ host_vendor = apple
 htmldir = ${docdir}
 includedir = ${prefix}/include
 infodir = ${datarootdir}/info
-install_sh = ${SHELL} /Users/taku/proj/crfpp/install-sh
+install_sh = ${SHELL} /crfpp/install-sh
 libdir = ${exec_prefix}/lib
 libexecdir = ${exec_prefix}/libexec
 localedir = ${datarootdir}/locale
diff --git a/Makefile.am b/Makefile.am
index 524a3d2..ee7dd5a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3,7 +3,7 @@ EXTRA_DIRS = doc example sdk perl python ruby java swig
 bin_PROGRAMS = crf_learn crf_test
 ACLOCAL_AMFLAGS = -I m4
 
-AUTOMAKE_OPTIONS = no-dependencies
+AUTOMAKE_OPTIONS = no-dependencies foreign
 lib_LTLIBRARIES = libcrfpp.la
 libcrfpp_la_SOURCES = crfpp.h thread.h libcrfpp.cpp lbfgs.cpp scoped_ptr.h param.cpp param.h encoder.cpp feature.cpp stream_wrapper.h \
                       feature_cache.cpp feature_index.cpp node.cpp path.cpp tagger.cpp \
diff --git a/common.h b/common.h
index 4269227..c271ac9 100644
--- a/common.h
+++ b/common.h
@@ -213,7 +213,7 @@ class string_buffer: public std::string {
   string_buffer& operator<<(unsigned short int _n) { _UITOA(_n); }
   string_buffer& operator<<(unsigned int _n)       { _UITOA(_n); }
   //  string_buffer& operator<<(unsigned long int _n)  { _UITOA(_n); }
-  string_buffer& operator<<(size_t _n)             { _UITOA(_n); }
+  // string_buffer& operator<<(size_t _n)             { _UITOA(_n); }
   string_buffer& operator<<(char _n) {
     push_back(_n);
     return *this;
diff --git a/configure b/configure
index 6d544e9..366a410 100755
--- a/configure
+++ b/configure
@@ -1,4 +1,4 @@
-#! /bin/sh
+#! /bin/bash
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.69.
 #
diff --git a/docker-build.sh b/docker-build.sh
index 8db18cb..ddd43ee 100644
--- a/docker-build.sh
+++ b/docker-build.sh
@@ -1,13 +1,17 @@
+#!/bin/bash
+
 ARCH=`uname -m`
 if [[ ARCH = "x86_64" ]]; then
     echo "Setting amd64" 
     export BUILD_ARCH=x86_64-unknown-linux-gnu
 else
-    echo "Setting arm64" 
-    export BUILD_ARCH=aarch64-unknown-linux-gnu 
+    echo "Setting arm v7" 
+    export BUILD_ARCH=arm-unknown-linux-gnueabihf
 fi
     echo "Done"
-    
+
+chmod +x configure 
+autoreconf -fi
 ./configure --build=$BUILD_ARCH 
 make 
 make install 
diff --git a/missing b/missing
index 64b5f90..0ff1942 100755
--- a/missing
+++ b/missing
@@ -1,4 +1,4 @@
-#! /bin/sh
+#! /bin/bash
 # Common stub for a few missing GNU programs while installing.
 
 scriptversion=2004-09-07.08