diff --git a/Makefile.am b/Makefile.am
index e144fb11e1e..b51f477b785 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -26,7 +26,9 @@ WINDOWS_PACKAGING = $(top_srcdir)/share/pixmaps/bitcoin.ico \
 
 OSX_PACKAGING = $(OSX_DEPLOY_SCRIPT) $(OSX_FANCY_PLIST) $(OSX_INSTALLER_ICONS) \
   $(top_srcdir)/contrib/macdeploy/background.png \
-  $(top_srcdir)/contrib/macdeploy/DS_Store
+  $(top_srcdir)/contrib/macdeploy/DS_Store \
+  $(top_srcdir)/contrib/macdeploy/detached-sig-apply.sh \
+  $(top_srcdir)/contrib/macdeploy/detached-sig-create.sh
 
 COVERAGE_INFO = baseline_filtered_combined.info baseline.info block_test.info \
   leveldb_baseline.info test_bitcoin_filtered.info total_coverage.info \
diff --git a/contrib/gitian-descriptors/gitian-osx-signer.yml b/contrib/gitian-descriptors/gitian-osx-signer.yml
new file mode 100644
index 00000000000..db9b4af93d0
--- /dev/null
+++ b/contrib/gitian-descriptors/gitian-osx-signer.yml
@@ -0,0 +1,37 @@
+---
+name: "bitcoin-dmg-signer"
+suites:
+- "precise"
+architectures:
+- "amd64"
+packages:
+- "libc6:i386"
+- "faketime"
+reference_datetime: "2013-06-01 00:00:00"
+remotes: []
+files:
+- "bitcoin-0.9.99-osx-unsigned.tar.gz"
+- "signature.tar.gz"
+script: |
+  WRAP_DIR=$HOME/wrapped
+  mkdir -p ${WRAP_DIR}
+  export PATH=`pwd`:$PATH
+  FAKETIME_PROGS="dmg genisoimage"
+
+  # Create global faketime wrappers
+  for prog in ${FAKETIME_PROGS}; do
+    echo '#!/bin/bash' > ${WRAP_DIR}/${prog}
+    echo "REAL=\`which -a ${prog} | grep -v ${WRAP_DIR}/${prog} | head -1\`" >> ${WRAP_DIR}/${prog}
+    echo 'export LD_PRELOAD=/usr/lib/faketime/libfaketime.so.1' >> ${WRAP_DIR}/${prog}
+    echo "export FAKETIME=\"${REFERENCE_DATETIME}\"" >> ${WRAP_DIR}/${prog}
+    echo "\$REAL \$@" >> $WRAP_DIR/${prog}
+    chmod +x ${WRAP_DIR}/${prog}
+  done
+
+  UNSIGNED=`echo bitcoin-*.tar.gz`
+  SIGNED=`echo ${UNSIGNED} | sed 's/.tar.*//' | sed 's/-unsigned//'`.dmg
+
+  tar -xf ${UNSIGNED}
+  ./detached-sig-apply.sh ${UNSIGNED} signature.tar.gz
+  ${WRAP_DIR}/genisoimage -no-cache-inodes -D -l -probe -V "Bitcoin-Qt" -no-pad -r -apple -o uncompressed.dmg signed-app
+  ${WRAP_DIR}/dmg dmg uncompressed.dmg ${OUTDIR}/${SIGNED}
diff --git a/contrib/gitian-descriptors/gitian-osx.yml b/contrib/gitian-descriptors/gitian-osx.yml
index cbe28e4f342..eb6df2096eb 100644
--- a/contrib/gitian-descriptors/gitian-osx.yml
+++ b/contrib/gitian-descriptors/gitian-osx.yml
@@ -106,8 +106,21 @@ script: |
     ./configure --prefix=${BASEPREFIX}/${i} --bindir=${INSTALLPATH}/bin --includedir=${INSTALLPATH}/include --libdir=${INSTALLPATH}/lib --disable-ccache --disable-maintainer-mode --disable-dependency-tracking ${CONFIGFLAGS}
     make ${MAKEOPTS}
     make install-strip
+
+    make deploydir
+    mkdir -p unsigned-app-${i}
+    cp contrib/macdeploy/detached-sig-apply.sh unsigned-app-${i}
+    cp contrib/macdeploy/detached-sig-create.sh unsigned-app-${i}
+    cp ${BASEPREFIX}/${i}/native/bin/dmg ${BASEPREFIX}/${i}/native/bin/genisoimage unsigned-app-${i}
+    cp ${BASEPREFIX}/${i}/native/bin/${i}-codesign_allocate unsigned-app-${i}/codesign_allocate
+    cp ${BASEPREFIX}/${i}/native/bin/${i}-pagestuff unsigned-app-${i}/pagestuff
+    mv dist unsigned-app-${i}
+    pushd unsigned-app-${i}
+    find . | sort | tar --no-recursion -czf ${OUTDIR}/${DISTNAME}-osx-unsigned.tar.gz -T -
+    popd
+
     make deploy
-    ${WRAP_DIR}/dmg dmg Bitcoin-Qt.dmg ${OUTDIR}/${DISTNAME}-osx.dmg
+    ${WRAP_DIR}/dmg dmg Bitcoin-Qt.dmg ${OUTDIR}/${DISTNAME}-osx-unsigned.dmg
 
     cd installed
     find . -name "lib*.la" -delete
diff --git a/contrib/macdeploy/detached-sig-apply.sh b/contrib/macdeploy/detached-sig-apply.sh
new file mode 100755
index 00000000000..7b3eb1b1974
--- /dev/null
+++ b/contrib/macdeploy/detached-sig-apply.sh
@@ -0,0 +1,53 @@
+#!/bin/sh
+set -e
+
+UNSIGNED=$1
+SIGNATURE=$2
+ARCH=x86_64
+ROOTDIR=dist
+BUNDLE=${ROOTDIR}/Bitcoin-Qt.app
+TEMPDIR=signed.temp
+OUTDIR=signed-app
+
+if [ -z "$UNSIGNED" ]; then
+  echo "usage: $0 <unsigned app> <signature>"
+  exit 1
+fi
+
+if [ -z "$SIGNATURE" ]; then
+  echo "usage: $0 <unsigned app> <signature>"
+  exit 1
+fi
+
+rm -rf ${TEMPDIR} && mkdir -p ${TEMPDIR}
+tar -C ${TEMPDIR} -xf ${UNSIGNED}
+tar -C ${TEMPDIR} -xf ${SIGNATURE}
+
+if [ -z "${PAGESTUFF}" ]; then
+  PAGESTUFF=${TEMPDIR}/pagestuff
+fi
+
+if [ -z "${CODESIGN_ALLOCATE}" ]; then
+  CODESIGN_ALLOCATE=${TEMPDIR}/codesign_allocate
+fi
+
+for i in `find ${TEMPDIR} -name "*.sign"`; do
+  SIZE=`stat -c %s ${i}`
+  TARGET_FILE=`echo ${i} | sed 's/\.sign$//'`
+
+  echo "Allocating space for the signature of size ${SIZE} in ${TARGET_FILE}"
+  ${CODESIGN_ALLOCATE} -i ${TARGET_FILE} -a ${ARCH} ${SIZE} -o ${i}.tmp
+
+  OFFSET=`${PAGESTUFF} ${i}.tmp -p | tail -2 | grep offset | sed 's/[^0-9]*//g'`
+  if [ -z ${QUIET} ]; then
+    echo "Attaching signature at offset ${OFFSET}"
+  fi
+
+  dd if=$i of=${i}.tmp bs=1 seek=${OFFSET} count=${SIZE} 2>/dev/null
+  mv ${i}.tmp ${TARGET_FILE}
+  rm ${i}
+  echo "Success."
+done
+mv ${TEMPDIR}/${ROOTDIR} ${OUTDIR}
+rm -rf ${TEMPDIR}
+echo "Signed: ${OUTDIR}"
diff --git a/contrib/macdeploy/detached-sig-create.sh b/contrib/macdeploy/detached-sig-create.sh
new file mode 100755
index 00000000000..aff4f08da8b
--- /dev/null
+++ b/contrib/macdeploy/detached-sig-create.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+set -e
+
+ROOTDIR=dist
+BUNDLE=${ROOTDIR}/Bitcoin-Qt.app
+CODESIGN=codesign
+TEMPDIR=sign.temp
+TEMPLIST=${TEMPDIR}/signatures.txt
+OUT=signature.tar.gz
+
+if [ ! -n "$1" ]; then
+  echo "usage: $0 <codesign args>"
+  echo "example: $0 -s MyIdentity"
+  exit 1
+fi
+
+rm -rf ${TEMPDIR} ${TEMPLIST}
+mkdir -p ${TEMPDIR}
+
+${CODESIGN} -f --file-list ${TEMPLIST} "$@" "${BUNDLE}"
+
+for i in `grep -v CodeResources ${TEMPLIST}`; do
+  TARGETFILE="${BUNDLE}/`echo ${i} | sed "s|.*${BUNDLE}/||"`"
+  SIZE=`pagestuff $i -p | tail -2 | grep size | sed 's/[^0-9]*//g'`
+  OFFSET=`pagestuff $i -p | tail -2 | grep offset | sed 's/[^0-9]*//g'`
+  SIGNFILE="${TEMPDIR}/${TARGETFILE}.sign"
+  DIRNAME="`dirname ${SIGNFILE}`"
+  mkdir -p "${DIRNAME}"
+  echo "Adding detached signature for: ${TARGETFILE}. Size: ${SIZE}. Offset: ${OFFSET}"
+  dd if=$i of=${SIGNFILE} bs=1 skip=${OFFSET} count=${SIZE} 2>/dev/null
+done
+
+for i in `grep CodeResources ${TEMPLIST}`; do
+  TARGETFILE="${BUNDLE}/`echo ${i} | sed "s|.*${BUNDLE}/||"`"
+  RESOURCE="${TEMPDIR}/${TARGETFILE}"
+  DIRNAME="`dirname "${RESOURCE}"`"
+  mkdir -p "${DIRNAME}"
+  echo "Adding resource for: "${TARGETFILE}""
+  cp "${i}" "${RESOURCE}"
+done
+
+rm ${TEMPLIST}
+
+tar -C ${TEMPDIR} -czf ${OUT} .
+rm -rf ${TEMPDIR}
+echo "Created ${OUT}"