diff --git a/.travis.yml b/.travis.yml
index eae07ead8..89b223865 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -31,7 +31,7 @@ matrix:
     - compiler: "true 3"
       env: HOST=x86_64-unknown-linux-gnu DEP_OPTS="NO_WALLET=1" RUN_TESTS=true GOAL="install" BITCOIN_CONFIG="--enable-glibc-back-compat"
     - compiler: "true 4"
-      env: HOST=i686-pc-linux-gnu PACKAGES="g++-multilib" RUN_TESTS=true GOAL="install" BITCOIN_CONFIG="--enable-glibc-back-compat"
+      env: HOST=i686-pc-linux-gnu PACKAGES="g++-multilib" RUN_TESTS=true GOAL="install" BITCOIN_CONFIG="--enable-glibc-back-compat" USE_SHELL="/bin/dash"
     - compiler: "true 5"
       env: HOST=x86_64-apple-darwin11 PACKAGES="gcc-multilib g++-multilib cmake libcap-dev libz-dev libbz2-dev" OSX_SDK=10.7 GOAL="deploy"
     - compiler: "true 6"
@@ -48,11 +48,12 @@ before_script:
     - if [ -n "$OSX_SDK" -a -f depends/sdk-sources/MacOSX${OSX_SDK}.sdk.tar.gz ]; then tar -C depends/SDKs -xf depends/sdk-sources/MacOSX${OSX_SDK}.sdk.tar.gz; fi
     - make $MAKEJOBS -C depends HOST=$HOST $DEP_OPTS || (echo "Build failure. Verbose build follows." && make -C depends V=1 HOST=$HOST $DEP_OPTS)
 script:
+    - if [ -n "$USE_SHELL" ]; then export CONFIG_SHELL="$USE_SHELL"; fi
     - OUTDIR=$BASE_OUTDIR/$TRAVIS_PULL_REQUEST/$TRAVIS_JOB_NUMBER-$HOST
     - BITCOIN_CONFIG_ALL="--disable-dependency-tracking --prefix=$TRAVIS_BUILD_DIR/depends/$HOST --bindir=$OUTDIR/bin --libdir=$OUTDIR/lib"
     - depends/$HOST/native/bin/ccache --max-size=$CCACHE_SIZE
     - if [ "$TRAVIS_PULL_REQUEST" != "false" ]; then export CCACHE_READONLY=1; fi
-    - ./autogen.sh
+    - test -n "$USE_SHELL" && eval '"$USE_SHELL" -c "./autogen.sh"' || ./autogen.sh
     - ./configure --cache-file=config.cache $BITCOIN_CONFIG_ALL $BITCOIN_CONFIG || ( cat config.log && false)
     - make distdir PACKAGE=bitcoin VERSION=$HOST
     - cd bitcoin-$HOST
diff --git a/autogen.sh b/autogen.sh
index ddfc09607..3e26a1830 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -3,6 +3,7 @@ set -e
 srcdir="$(dirname $0)"
 cd "$srcdir"
 if [ -z ${LIBTOOLIZE} ] && GLIBTOOLIZE="`which glibtoolize 2>/dev/null`"; then
-  export LIBTOOLIZE="${GLIBTOOLIZE}"
+  LIBTOOLIZE="${GLIBTOOLIZE}"
+  export LIBTOOLIZE
 fi
 autoreconf --install --force --warnings=all
diff --git a/build-aux/m4/bitcoin_qt.m4 b/build-aux/m4/bitcoin_qt.m4
index 71b148489..2a7226265 100644
--- a/build-aux/m4/bitcoin_qt.m4
+++ b/build-aux/m4/bitcoin_qt.m4
@@ -84,7 +84,7 @@ dnl Outputs: bitcoin_enable_qt, bitcoin_enable_qt_dbus, bitcoin_enable_qt_test
 AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   use_pkgconfig=$1
 
-  if test x$use_pkgconfig == x; then
+  if test x$use_pkgconfig = x; then
     use_pkgconfig=yes
   fi
 
@@ -106,9 +106,9 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   BITCOIN_QT_CHECK([
   TEMP_CPPFLAGS=$CPPFLAGS
   CPPFLAGS=$QT_INCLUDES
-  if test x$bitcoin_qt_got_major_vers == x5; then
+  if test x$bitcoin_qt_got_major_vers = x5; then
     _BITCOIN_QT_IS_STATIC
-    if test x$bitcoin_cv_static_qt == xyes; then
+    if test x$bitcoin_cv_static_qt = xyes; then
       AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
       if test x$qt_plugin_path != x; then
         QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
@@ -118,14 +118,14 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
         PKG_CHECK_MODULES([QTPLATFORM], [Qt5PlatformSupport], [QT_LIBS="$QTPLATFORM_LIBS $QT_LIBS"])
       fi
       _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(AccessibleFactory)], [-lqtaccessiblewidgets])
-      if test x$TARGET_OS == xwindows; then
+      if test x$TARGET_OS = xwindows; then
         _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QWindowsIntegrationPlugin)],[-lqwindows])
         AC_DEFINE(QT_QPA_PLATFORM_WINDOWS, 1, [Define this symbol if the qt platform is windows])
-      elif test x$TARGET_OS == xlinux; then
+      elif test x$TARGET_OS = xlinux; then
         PKG_CHECK_MODULES([X11XCB], [x11-xcb], [QT_LIBS="$X11XCB_LIBS $QT_LIBS"])
         _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QXcbIntegrationPlugin)],[-lqxcb -lxcb-static])
         AC_DEFINE(QT_QPA_PLATFORM_XCB, 1, [Define this symbol if the qt platform is xcb])
-      elif test x$TARGET_OS == xdarwin; then
+      elif test x$TARGET_OS = xdarwin; then
         if test x$use_pkgconfig = xyes; then
           PKG_CHECK_MODULES([QTPRINT], [Qt5PrintSupport], [QT_LIBS="$QTPRINT_LIBS $QT_LIBS"])
         fi
@@ -135,7 +135,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
       fi
     fi
   else
-    if test x$TARGET_OS == xwindows; then
+    if test x$TARGET_OS = xwindows; then
       AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
       if test x$qt_plugin_path != x; then
         QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
@@ -196,7 +196,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
     if test x$use_dbus = xyes && test x$have_qt_dbus = xno; then
       AC_MSG_ERROR("libQtDBus not found. Install libQtDBus or remove --with-qtdbus.")
     fi
-    if test x$LUPDATE == x; then
+    if test x$LUPDATE = x; then
       AC_MSG_WARN("lupdate is required to update qt translations")
     fi
   ],[
@@ -291,10 +291,10 @@ dnl Outputs: have_qt_test and have_qt_dbus are set (if applicable) to yes|no.
 AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITH_PKGCONFIG],[
   m4_ifdef([PKG_CHECK_MODULES],[
   auto_priority_version=$1
-  if test x$auto_priority_version == x; then
+  if test x$auto_priority_version = x; then
     auto_priority_version=qt5
   fi
-    if test x$bitcoin_qt_want_version == xqt5 ||  ( test x$bitcoin_qt_want_version == xauto && test x$auto_priority_version == xqt5 ); then
+    if test x$bitcoin_qt_want_version = xqt5 ||  ( test x$bitcoin_qt_want_version = xauto && test x$auto_priority_version = xqt5 ); then
       QT_LIB_PREFIX=Qt5
       bitcoin_qt_got_major_vers=5
     else
@@ -304,14 +304,14 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITH_PKGCONFIG],[
     qt5_modules="Qt5Core Qt5Gui Qt5Network Qt5Widgets"
     qt4_modules="QtCore QtGui QtNetwork"
     BITCOIN_QT_CHECK([
-      if test x$bitcoin_qt_want_version == xqt5 || ( test x$bitcoin_qt_want_version == xauto && test x$auto_priority_version == xqt5 ); then
+      if test x$bitcoin_qt_want_version = xqt5 || ( test x$bitcoin_qt_want_version = xauto && test x$auto_priority_version = xqt5 ); then
         PKG_CHECK_MODULES([QT], [$qt5_modules], [QT_INCLUDES="$QT_CFLAGS"; have_qt=yes],[have_qt=no])
-      elif test x$bitcoin_qt_want_version == xqt4 || ( test x$bitcoin_qt_want_version == xauto && test x$auto_priority_version == xqt4 ); then
+      elif test x$bitcoin_qt_want_version = xqt4 || ( test x$bitcoin_qt_want_version = xauto && test x$auto_priority_version = xqt4 ); then
         PKG_CHECK_MODULES([QT], [$qt4_modules], [QT_INCLUDES="$QT_CFLAGS"; have_qt=yes], [have_qt=no])
       fi
 
       dnl qt version is set to 'auto' and the preferred version wasn't found. Now try the other.
-      if test x$have_qt == xno && test x$bitcoin_qt_want_version == xauto; then
+      if test x$have_qt = xno && test x$bitcoin_qt_want_version = xauto; then
         if test x$auto_priority_version = x$qt5; then
           PKG_CHECK_MODULES([QT], [$qt4_modules], [QT_INCLUDES="$QT_CFLAGS"; have_qt=yes; QT_LIB_PREFIX=Qt; bitcoin_qt_got_major_vers=4], [have_qt=no])
         else
@@ -358,7 +358,7 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
     if test x$bitcoin_qt_want_version = xauto; then
       _BITCOIN_QT_CHECK_QT5
     fi
-    if test x$bitcoin_cv_qt5 == xyes || test x$bitcoin_qt_want_version = xqt5; then
+    if test x$bitcoin_cv_qt5 = xyes || test x$bitcoin_qt_want_version = xqt5; then
       QT_LIB_PREFIX=Qt5
       bitcoin_qt_got_major_vers=5
     else
@@ -373,7 +373,7 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
       LIBS="$LIBS -L$qt_lib_path"
     fi
 
-    if test x$TARGET_OS == xwindows; then
+    if test x$TARGET_OS = xwindows; then
       AC_CHECK_LIB([imm32],      [main],, BITCOIN_QT_FAIL(libimm32 not found))
     fi
   ])
@@ -385,7 +385,7 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Core]   ,[main],,BITCOIN_QT_FAIL(lib$QT_LIB_PREFIXCore not found)))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Gui]    ,[main],,BITCOIN_QT_FAIL(lib$QT_LIB_PREFIXGui not found)))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Network],[main],,BITCOIN_QT_FAIL(lib$QT_LIB_PREFIXNetwork not found)))
-  if test x$bitcoin_qt_got_major_vers == x5; then
+  if test x$bitcoin_qt_got_major_vers = x5; then
     BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Widgets],[main],,BITCOIN_QT_FAIL(lib$QT_LIB_PREFIXWidgets not found)))
   fi
   QT_LIBS="$LIBS"
diff --git a/configure.ac b/configure.ac
index abf9f39e6..0bd309a3a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -250,14 +250,16 @@ case $host in
          bdb_prefix=`$BREW --prefix berkeley-db4 2>/dev/null`
          qt5_prefix=`$BREW --prefix qt5 2>/dev/null`
          if test x$openssl_prefix != x; then
-           export PKG_CONFIG_PATH="$openssl_prefix/lib/pkgconfig:$PKG_CONFIG_PATH"
+           PKG_CONFIG_PATH="$openssl_prefix/lib/pkgconfig:$PKG_CONFIG_PATH"
+           export PKG_CONFIG_PATH
          fi
          if test x$bdb_prefix != x; then
            CPPFLAGS="$CPPFLAGS -I$bdb_prefix/include"
            LIBS="$LIBS -L$bdb_prefix/lib"
          fi
          if test x$qt5_prefix != x; then
-           export PKG_CONFIG_PATH="$qt5_prefix/lib/pkgconfig:$PKG_CONFIG_PATH"
+           PKG_CONFIG_PATH="$qt5_prefix/lib/pkgconfig:$PKG_CONFIG_PATH"
+           export PKG_CONFIG_PATH
          fi
        fi
      else
@@ -287,7 +289,7 @@ if test x$use_comparison_tool != xno; then
 fi
 
 if test x$use_comparison_tool_reorg_tests != xno; then
-  if test x$use_comparison_tool == x; then
+  if test x$use_comparison_tool = x; then
     AC_MSG_ERROR("comparison tool reorg tests but comparison tool was not specified")
   fi
   AC_SUBST(COMPARISON_TOOL_REORG_TESTS, 1)
@@ -295,20 +297,20 @@ else
   AC_SUBST(COMPARISON_TOOL_REORG_TESTS, 0)
 fi
 
-if test x$use_lcov == xyes; then
-  if test x$LCOV == x; then
+if test x$use_lcov = xyes; then
+  if test x$LCOV = x; then
     AC_MSG_ERROR("lcov testing requested but lcov not found")
   fi
-  if test x$GCOV == x; then
+  if test x$GCOV = x; then
     AC_MSG_ERROR("lcov testing requested but gcov not found")
   fi
-  if test x$JAVA == x; then
+  if test x$JAVA = x; then
     AC_MSG_ERROR("lcov testing requested but java not found")
   fi
-  if test x$GENHTML == x; then
+  if test x$GENHTML = x; then
     AC_MSG_ERROR("lcov testing requested but genhtml not found")
   fi
-  if test x$use_comparison_tool == x; then
+  if test x$use_comparison_tool = x; then
     AC_MSG_ERROR("lcov testing requested but comparison tool was not specified")
   fi
   LCOV="$LCOV --gcov-tool=$GCOV"
@@ -607,7 +609,7 @@ BITCOIN_QT_INIT
 
 if test x$use_pkgconfig = xyes; then
 
-  if test x"$PKG_CONFIG" == "x"; then
+  if test x"$PKG_CONFIG" = "x"; then
     AC_MSG_ERROR(pkg-config not found.)
   fi
 
@@ -721,7 +723,7 @@ if test x$bitcoin_enable_qt != xno; then
   dnl enable qr support
   AC_MSG_CHECKING([whether to build GUI with support for QR codes])
   if test x$have_qrencode = xno; then
-    if test x$use_qr == xyes; then
+    if test x$use_qr = xyes; then
      AC_MSG_ERROR("QR support requested but cannot be built. use --without-qrencode")
     fi
     AC_MSG_RESULT(no)
@@ -735,7 +737,7 @@ if test x$bitcoin_enable_qt != xno; then
     fi
   fi
 
-  if test x$XGETTEXT == x; then
+  if test x$XGETTEXT = x; then
     AC_MSG_WARN("xgettext is required to update qt translations")
   fi
 
@@ -770,12 +772,12 @@ fi
 AM_CONDITIONAL([TARGET_DARWIN], [test x$TARGET_OS = xdarwin])
 AM_CONDITIONAL([BUILD_DARWIN], [test x$BUILD_OS = xdarwin])
 AM_CONDITIONAL([TARGET_WINDOWS], [test x$TARGET_OS = xwindows])
-AM_CONDITIONAL([ENABLE_WALLET],[test x$enable_wallet == xyes])
-AM_CONDITIONAL([ENABLE_TESTS],[test x$use_tests == xyes])
-AM_CONDITIONAL([ENABLE_QT],[test x$bitcoin_enable_qt == xyes])
+AM_CONDITIONAL([ENABLE_WALLET],[test x$enable_wallet = xyes])
+AM_CONDITIONAL([ENABLE_TESTS],[test x$use_tests = xyes])
+AM_CONDITIONAL([ENABLE_QT],[test x$bitcoin_enable_qt = xyes])
 AM_CONDITIONAL([ENABLE_QT_TESTS],[test x$use_tests$bitcoin_enable_qt_test = xyesyes])
 AM_CONDITIONAL([USE_QRCODE], [test x$use_qr = xyes])
-AM_CONDITIONAL([USE_LCOV],[test x$use_lcov == xyes])
+AM_CONDITIONAL([USE_LCOV],[test x$use_lcov = xyes])
 AM_CONDITIONAL([USE_COMPARISON_TOOL],[test x$use_comparison_tool != xno])
 AM_CONDITIONAL([USE_COMPARISON_TOOL_REORG_TESTS],[test x$use_comparison_tool_reorg_test != xno])
 AM_CONDITIONAL([GLIBC_BACK_COMPAT],[test x$use_glibc_compat = xyes])
diff --git a/contrib/devtools/github-merge.sh b/contrib/devtools/github-merge.sh
index 3217a0619..a83a2a59b 100755
--- a/contrib/devtools/github-merge.sh
+++ b/contrib/devtools/github-merge.sh
@@ -13,7 +13,7 @@
 # name $BRANCH is overwritten with the merged result, and optionally pushed.
 
 REPO="$(git config --get githubmerge.repository)"
-if [[ "d$REPO" == "d" ]]; then
+if [ "d$REPO" = "d" ]; then
   echo "ERROR: No repository configured. Use this command to set:" >&2
   echo "git config githubmerge.repository <owner>/<repo>" >&2
   echo "In addition, you can set the following variables:" >&2
@@ -24,12 +24,12 @@ if [[ "d$REPO" == "d" ]]; then
 fi
 
 HOST="$(git config --get githubmerge.host)"
-if [[ "d$HOST" == "d" ]]; then
+if [ "d$HOST" = "d" ]; then
   HOST="git@github.com"
 fi
 
 BRANCH="$(git config --get githubmerge.branch)"
-if [[ "d$BRANCH" == "d" ]]; then
+if [ "d$BRANCH" = "d" ]; then
   BRANCH="master"
 fi
 
@@ -37,12 +37,12 @@ TESTCMD="$(git config --get githubmerge.testcmd)"
 
 PULL="$1"
 
-if [[ "d$PULL" == "d" ]]; then
+if [ "d$PULL" = "d" ]; then
   echo "Usage: $0 pullnumber [branch]" >&2
   exit 2
 fi
 
-if [[ "d$2" != "d" ]]; then
+if [ "d$2" != "d" ]; then
   BRANCH="$2"
 fi
 
@@ -101,7 +101,7 @@ else
 fi
 
 # Run test command if configured.
-if [[ "d$TESTCMD" != "d" ]]; then
+if [ "d$TESTCMD" != "d" ]; then
   # Go up to the repository's root.
   while [ ! -d .git ]; do cd ..; done
   if ! $TESTCMD; then
@@ -112,10 +112,10 @@ if [[ "d$TESTCMD" != "d" ]]; then
   # Show the created merge.
   git diff pull/"$PULL"/merge..pull/"$PULL"/local-merge >"$TMPDIR"/diff
   git diff pull/"$PULL"/base..pull/"$PULL"/local-merge
-  if [[ "$(<"$TMPDIR"/diff)" != "" ]]; then
+  if [ "$(<"$TMPDIR"/diff)" != "" ]; then
     echo "WARNING: merge differs from github!" >&2
     read -p "Type 'ignore' to continue. " -r >&2
-    if [[ "d$REPLY" =~ ^d[iI][gG][nN][oO][rR][eE]$ ]]; then
+    if [ "d$REPLY" =~ ^d[iI][gG][nN][oO][rR][eE]$ ]; then
       echo "Difference with github ignored." >&2
     else
       cleanup
@@ -124,7 +124,7 @@ if [[ "d$TESTCMD" != "d" ]]; then
   fi
   read -p "Press 'd' to accept the diff. " -n 1 -r >&2
   echo
-  if [[ "d$REPLY" =~ ^d[dD]$ ]]; then
+  if [ "d$REPLY" =~ ^d[dD]$ ]; then
     echo "Diff accepted." >&2
   else
     echo "ERROR: Diff rejected." >&2
@@ -139,7 +139,7 @@ else
   bash -i
   read -p "Press 'm' to accept the merge. " -n 1 -r >&2
   echo
-  if [[ "d$REPLY" =~ ^d[Mm]$ ]]; then
+  if [ "d$REPLY" =~ ^d[Mm]$ ]; then
     echo "Merge accepted." >&2
   else
     echo "ERROR: Merge rejected." >&2
@@ -151,8 +151,8 @@ fi
 # Sign the merge commit.
 read -p "Press 's' to sign off on the merge. " -n 1 -r >&2
 echo
-if [[ "d$REPLY" =~ ^d[Ss]$ ]]; then
-  if [[ "$(git config --get user.signingkey)" == "" ]]; then
+if [ "d$REPLY" =~ ^d[Ss]$ ]; then
+  if [ "$(git config --get user.signingkey)" = "" ]; then
     echo "WARNING: No GPG signing key set, not signing. Set one using:" >&2
     echo "git config --global user.signingkey <key>" >&2
     git commit -q --signoff --amend --no-edit
@@ -168,6 +168,6 @@ cleanup
 
 # Push the result.
 read -p "Type 'push' to push the result to $HOST:$REPO, branch $BRANCH. " -r >&2
-if [[ "d$REPLY" =~ ^d[Pp][Uu][Ss][Hh]$ ]]; then
+if [ "d$REPLY" =~ ^d[Pp][Uu][Ss][Hh]$ ]; then
   git push "$HOST":"$REPO" refs/heads/"$BRANCH"
 fi
diff --git a/contrib/gitian-descriptors/boost-win.yml b/contrib/gitian-descriptors/boost-win.yml
index db5d6bab1..347952e3a 100644
--- a/contrib/gitian-descriptors/boost-win.yml
+++ b/contrib/gitian-descriptors/boost-win.yml
@@ -29,7 +29,7 @@ script: |
     #
     INSTALLPREFIX=$HOME/staging${BITS}
     BUILDDIR=$HOME/build${BITS}
-    if [ "$BITS" == "32" ]; then
+    if [ "x$BITS" = "x32" ]; then
       HOST=i686-w64-mingw32
     else
       HOST=x86_64-w64-mingw32
diff --git a/contrib/gitian-descriptors/deps-win.yml b/contrib/gitian-descriptors/deps-win.yml
index fabc2949e..fe02950ef 100644
--- a/contrib/gitian-descriptors/deps-win.yml
+++ b/contrib/gitian-descriptors/deps-win.yml
@@ -39,7 +39,7 @@ script: |
     #
     INSTALLPREFIX=$HOME/staging${BITS}
     BUILDDIR=$HOME/build${BITS}
-    if [ "$BITS" == "32" ]; then
+    if [ "x$BITS" = "x32" ]; then
       HOST=i686-w64-mingw32
     else
       HOST=x86_64-w64-mingw32
@@ -50,7 +50,7 @@ script: |
     #
     tar xzf $INDIR/openssl-1.0.1h.tar.gz
     cd openssl-1.0.1h
-    if [ "$BITS" == "32" ]; then
+    if [ "x$BITS" = "x32" ]; then
       OPENSSL_TGT=mingw
     else
       OPENSSL_TGT=mingw64
diff --git a/contrib/gitian-descriptors/gitian-win.yml b/contrib/gitian-descriptors/gitian-win.yml
index 245f15cca..b2795c537 100644
--- a/contrib/gitian-descriptors/gitian-win.yml
+++ b/contrib/gitian-descriptors/gitian-win.yml
@@ -50,7 +50,7 @@ script: |
     STAGING=$HOME/staging${BITS}
     BUILDDIR=$HOME/build${BITS}
     BINDIR=$OUTDIR/$BITS
-    if [ "$BITS" == "32" ]; then
+    if [ "x$BITS" = "x32" ]; then
       HOST=i686-w64-mingw32
     else
       HOST=x86_64-w64-mingw32
@@ -63,7 +63,7 @@ script: |
     unzip $INDIR/boost-win${BITS}-1.55.0-gitian-r6.zip
     unzip $INDIR/bitcoin-deps-win${BITS}-gitian-r13.zip
     unzip $INDIR/protobuf-win${BITS}-2.5.0-gitian-r4.zip
-    if [ "$NEEDDIST" == "1" ]; then
+    if [ "x$NEEDDIST" = "x1" ]; then
       # Make source code archive which is architecture independent so it only needs to be done once
       cd $HOME/build/bitcoin
       ./autogen.sh
diff --git a/contrib/gitian-descriptors/protobuf-win.yml b/contrib/gitian-descriptors/protobuf-win.yml
index d2fdcaa7f..1b7af0884 100644
--- a/contrib/gitian-descriptors/protobuf-win.yml
+++ b/contrib/gitian-descriptors/protobuf-win.yml
@@ -26,7 +26,7 @@ script: |
     #
     INSTALLPREFIX=$HOME/staging${BITS}
     BUILDDIR=$HOME/build${BITS}
-    if [ "$BITS" == "32" ]; then
+    if [ "x$BITS" = "x32" ]; then
       HOST=i686-w64-mingw32
     else
       HOST=x86_64-w64-mingw32
diff --git a/contrib/gitian-descriptors/qt-linux.yml b/contrib/gitian-descriptors/qt-linux.yml
index b163b4bb8..fd86b4df1 100644
--- a/contrib/gitian-descriptors/qt-linux.yml
+++ b/contrib/gitian-descriptors/qt-linux.yml
@@ -18,7 +18,7 @@ files:
 script: |
   export FAKETIME=$REFERENCE_DATETIME
   export TZ=UTC
-  if [ "$GBUILD_BITS" == "32" ]; then
+  if [ "x$GBUILD_BITS" = "x32" ]; then
     ARCH='i386-linux-gnu'
   else
     ARCH='x86_64-linux-gnu'
@@ -74,7 +74,7 @@ script: |
   #endif
   ' > $QCONFIG
 
-  if [ "$GBUILD_BITS" == "32" ]; then
+  if [ "x$GBUILD_BITS" = "x32" ]; then
     echo '
   /* Machine byte-order */
   #define Q_BIG_ENDIAN 4321
diff --git a/contrib/gitian-descriptors/qt-win.yml b/contrib/gitian-descriptors/qt-win.yml
index 7000c7005..57bc4c318 100644
--- a/contrib/gitian-descriptors/qt-win.yml
+++ b/contrib/gitian-descriptors/qt-win.yml
@@ -38,7 +38,7 @@ script: |
     INSTALLPREFIX=$HOME/staging${BITS}
     BUILDDIR=$HOME/build${BITS}
     DEPSDIR=$HOME/deps${BITS}
-    if [ "$BITS" == "32" ]; then
+    if [ "x$BITS" = "x32" ]; then
       HOST=i686-w64-mingw32
     else
       HOST=x86_64-w64-mingw32
diff --git a/depends/config.site.in b/depends/config.site.in
index 3426050cd..df076956b 100644
--- a/depends/config.site.in
+++ b/depends/config.site.in
@@ -34,12 +34,12 @@ if test -z $with_gui && test -n "@no_qt@"; then
   with_gui=no
 fi
 
-if test @host_os@ == darwin; then
+if test x@host_os@ = xdarwin; then
   BREW=no
   PORT=no
 fi
 
-if test @host_os@ == mingw32; then
+if test x@host_os@ = xmingw32; then
   if test -z $with_qt_incdir; then
     with_qt_incdir=$prefix/include
   fi
diff --git a/qa/rpc-tests/send.sh b/qa/rpc-tests/send.sh
index bfbf791d0..8c0f11459 100755
--- a/qa/rpc-tests/send.sh
+++ b/qa/rpc-tests/send.sh
@@ -14,7 +14,7 @@ if [ $# -eq 0 ]; then
   exit 0
 fi
 
-if [ $1 == "-STOP" ]; then
+if [ $1 = "-STOP" ]; then
   if [ -s ${PIDFILE} ]; then
       kill -s ${SIGNAL} $(<${PIDFILE})
   fi
diff --git a/qa/rpc-tests/walletbackup.sh b/qa/rpc-tests/walletbackup.sh
index 744467098..b88d5920f 100755
--- a/qa/rpc-tests/walletbackup.sh
+++ b/qa/rpc-tests/walletbackup.sh
@@ -149,7 +149,7 @@ echo "Creating transactions..."
 
 function S {
   TXID=$( $CLI -datadir=${D}/node${1} sendtoaddress ${2} "${3}" 0 )
-  if [[ $TXID == "" ]] ; then
+  if [ x$TXID = x ] ; then
       echoerr "node${1}: error sending ${3} btc"
       echo -n "node${1} balance: "
       $CLI -datadir=${D}/node${1} getbalance "*" 0