diff --git a/sysc/init b/sysc/init
index 8c015283..1ad2cb41 100755
--- a/sysc/init
+++ b/sysc/init
@@ -14,6 +14,7 @@ export DESTDIR=/tmp/destdir
 export DISTFILES=/distfiles
 export SRCDIR="${SOURCES}"
 export HOME=/tmp
+export SOURCE_DATE_EPOCH=0
 
 # shellcheck source=sysa/helpers.sh
 . "${SOURCES}/helpers.sh"
diff --git a/sysc/run.sh b/sysc/run.sh
index 02877686..f8502eb8 100755
--- a/sysc/run.sh
+++ b/sysc/run.sh
@@ -55,4 +55,4 @@ fi
 
 build bash-5.1
 
-exec env -i PATH="${PATH}" PREFIX="${PREFIX}" SOURCES="${SOURCES}" DESTDIR="${DESTDIR}" DISTFILES="${DISTFILES}" SRCDIR="${SRCDIR}" HOME="${HOME}" bash run2.sh
+exec env -i PATH="${PATH}" PREFIX="${PREFIX}" SOURCES="${SOURCES}" DESTDIR="${DESTDIR}" DISTFILES="${DISTFILES}" SRCDIR="${SRCDIR}" HOME="${HOME}" SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH}" bash run2.sh
diff --git a/sysc/run2.sh b/sysc/run2.sh
index a30da3f6..2fb666e2 100755
--- a/sysc/run2.sh
+++ b/sysc/run2.sh
@@ -126,4 +126,4 @@ if [ -e after.sh ]; then
     FILE=after.sh
 fi
 
-exec env -i PATH="${PATH}" PREFIX="${PREFIX}" SOURCES="${SOURCES}" DESTDIR="${DESTDIR}" DISTFILES="${DISTFILES}" HOME="${HOME}" bash ${FILE}
+exec env -i PATH="${PATH}" PREFIX="${PREFIX}" SOURCES="${SOURCES}" DESTDIR="${DESTDIR}" DISTFILES="${DISTFILES}" HOME="${HOME}" SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH}" bash ${FILE}