diff --git a/git-clone.sh b/git-clone.sh
index 24ad179bbd..ecf9d89a10 100755
--- a/git-clone.sh
+++ b/git-clone.sh
@@ -229,7 +229,7 @@ cleanup() {
 trap cleanup 0
 mkdir -p "$dir" && D=$(cd "$dir" && pwd) || usage
 test -n "$GIT_WORK_TREE" && mkdir -p "$GIT_WORK_TREE" &&
-W=$(cd "$GIT_WORK_TREE" && pwd) && export GIT_WORK_TREE="$W"
+W=$(cd "$GIT_WORK_TREE" && pwd) && GIT_WORK_TREE="$W" && export GIT_WORK_TREE
 if test yes = "$bare" || test -n "$GIT_WORK_TREE"; then
 	GIT_DIR="$D"
 else
diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 674a25d27e..29d35fd27c 100755
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -66,17 +66,17 @@ set_ident () {
 			h
 			s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
 			s/'\''/'\''\'\'\''/g
-			s/.*/export GIT_'$uid'_NAME='\''&'\''/p
+			s/.*/GIT_'$uid'_NAME='\''&'\''; export GIT_'$uid'_NAME/p
 
 			g
 			s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
 			s/'\''/'\''\'\'\''/g
-			s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
+			s/.*/GIT_'$uid'_EMAIL='\''&'\''; export GIT_'$uid'_EMAIL/p
 
 			g
 			s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
 			s/'\''/'\''\'\'\''/g
-			s/.*/export GIT_'$uid'_DATE='\''&'\''/p
+			s/.*/GIT_'$uid'_DATE='\''&'\''; export GIT_'$uid'_DATE/p
 
 			q
 		}
@@ -84,7 +84,7 @@ set_ident () {
 
 	LANG=C LC_ALL=C sed -ne "$pick_id_script"
 	# Ensure non-empty id name.
-	echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
+	echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
 }
 
 USAGE="[--env-filter <command>] [--tree-filter <command>] \
@@ -206,7 +206,8 @@ done < "$tempdir"/backup-refs
 ORIG_GIT_DIR="$GIT_DIR"
 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
-export GIT_DIR GIT_WORK_TREE=.
+GIT_WORK_TREE=.
+export GIT_DIR GIT_WORK_TREE
 
 # These refs should be updated if their heads were rewritten
 
@@ -231,7 +232,8 @@ done > "$tempdir"/heads
 test -s "$tempdir"/heads ||
 	die "Which ref do you want to rewrite?"
 
-export GIT_INDEX_FILE="$(pwd)/../index"
+GIT_INDEX_FILE="$(pwd)/../index"
+export GIT_INDEX_FILE
 git read-tree || die "Could not seed the index"
 
 ret=0
@@ -267,7 +269,8 @@ while read commit parents; do
 		git read-tree -i -m $commit:"$filter_subdir"
 	esac || die "Could not initialize the index"
 
-	export GIT_COMMIT=$commit
+	GIT_COMMIT=$commit
+	export GIT_COMMIT
 	git cat-file commit "$commit" >../commit ||
 		die "Cannot read commit $commit"
 
@@ -401,7 +404,8 @@ if [ "$filter_tag_name" ]; then
 
 		[ -f "../map/$sha1" ] || continue
 		new_sha1="$(cat "../map/$sha1")"
-		export GIT_COMMIT="$sha1"
+		GIT_COMMIT="$sha1"
+		export GIT_COMMIT
 		new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
 			die "tag name filter failed: $filter_tag_name"
 
diff --git a/git-quiltimport.sh b/git-quiltimport.sh
index 6b0c4d2f27..233e5eae1d 100755
--- a/git-quiltimport.sh
+++ b/git-quiltimport.sh
@@ -77,8 +77,9 @@ for patch_name in $(grep -v '^#' < "$QUILT_PATCHES/series" ); do
 	}
 
 	# Parse the author information
-	export GIT_AUTHOR_NAME=$(sed -ne 's/Author: //p' "$tmp_info")
-	export GIT_AUTHOR_EMAIL=$(sed -ne 's/Email: //p' "$tmp_info")
+	GIT_AUTHOR_NAME=$(sed -ne 's/Author: //p' "$tmp_info")
+	GIT_AUTHOR_EMAIL=$(sed -ne 's/Email: //p' "$tmp_info")
+	export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL
 	while test -z "$GIT_AUTHOR_EMAIL" && test -z "$GIT_AUTHOR_NAME" ; do
 		if [ -n "$quilt_author" ] ; then
 			GIT_AUTHOR_NAME="$quilt_author_name";
@@ -104,8 +105,9 @@ for patch_name in $(grep -v '^#' < "$QUILT_PATCHES/series" ); do
 			GIT_AUTHOR_EMAIL="$patch_author_email"
 		fi
 	done
-	export GIT_AUTHOR_DATE=$(sed -ne 's/Date: //p' "$tmp_info")
-	export SUBJECT=$(sed -ne 's/Subject: //p' "$tmp_info")
+	GIT_AUTHOR_DATE=$(sed -ne 's/Date: //p' "$tmp_info")
+	SUBJECT=$(sed -ne 's/Subject: //p' "$tmp_info")
+	export GIT_AUTHOR_DATE SUBJECT
 	if [ -z "$SUBJECT" ] ; then
 		SUBJECT=$(echo $patch_name | sed -e 's/.patch$//')
 	fi