diff --git a/git-rebase-first-parent b/git-rebase-first-parent
index ad11d1d..c44a604 100755
--- a/git-rebase-first-parent
+++ b/git-rebase-first-parent
@@ -43,10 +43,11 @@ die() {
 OPTS_SPEC="\
 git rebase-first-parent [-i | --interactive] [--onto <newbase>] [<upstream> [<branch>]]
 --
-h,help        show the help
+h,help!        show the help
 
-i,interactive let the user edit the list of commits to rebase
-onto=newbase  rebase onto given branch instead of upstream"
+i,interactive! let the user edit the list of commits to rebase
+x,exec!=cmd run command after each commit (e.g. to check compilation)
+onto!=newbase  rebase onto given branch instead of upstream"
 
 usage() {
 	if [ $# -gt 0 ]; then
@@ -60,6 +61,7 @@ eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt --stuck-long -- "$@" || ech
 
 unset INTERACTIVE
 unset ONTO
+GIT_REBASE_FIRST_PARENT_EXEC_CMDS=
 while [ $# -gt 0 ]; do
 	case "$1" in
 	--interactive)
@@ -68,6 +70,9 @@ while [ $# -gt 0 ]; do
 	--onto=*)
 		ONTO="${1#--onto=}"
 		;;
+	--exec=*)
+		GIT_REBASE_FIRST_PARENT_EXEC_CMDS="${GIT_REBASE_FIRST_PARENT_EXEC_CMDS}exec ${1#--exec=}\n"
+		;;
 	--)
 		shift
 		break
@@ -115,5 +120,8 @@ if [ -n "${INTERACTIVE+set}" ]; then
 	fi
 	export GIT_REBASE_FIRST_PARENT_SEQUENCE_EDITOR
 fi
+# The variable GIT_REBASE_FIRST_PARENT_EXEC_CMDS is interpreted by
+# make-rebase-first-parent to add extra "exec" lines to each rebase step.
+export GIT_REBASE_FIRST_PARENT_EXEC_CMDS
 
 env GIT_SEQUENCE_EDITOR=git-rebase-first-parent-sequence-editor GIT_REBASE_FIRST_PARENT_UPSTREAM="$UPSTREAM" GIT_REBASE_FIRST_PARENT_BRANCH="$BRANCH" git rebase "$@"
diff --git a/make-rebase-first-parent b/make-rebase-first-parent
index cb6f4ac..6f9cd04 100755
--- a/make-rebase-first-parent
+++ b/make-rebase-first-parent
@@ -45,13 +45,16 @@ git log --first-parent --reverse --format='tformat:%H %P#%s' "$1".."$2" | while
 	l="${l%%#*}"
 	c="${l%% *}"
 	p="${l#* }"
-	p="`echo "$p" | sed 's/^[[:space:]]*[^[:space:]]\{1,\}//;s/[[:space:]]*\([^[:space:]]\{1,\}\)/ -p \1/g'`"
+	p="$(echo "$p" | sed 's/^[[:space:]]*[^[:space:]]\{1,\}//;s/[[:space:]]*\([^[:space:]]\{1,\}\)/ -p \1/g')"
 	if [ -z "$p" ]; then
 		printf 'pick %s %s\n' "$c" "$s"
 	else
 		printf '# %s\n' "$s"
 		echo "exec git update-ref HEAD \`git commit-tree -p HEAD$p -m 'dummy merge for $c' 'HEAD^{tree}'\` && git cherry-pick -n -m 1 $c && git commit --amend -q -n -C $c"
 	fi
+	if [ -n "${GIT_REBASE_FIRST_PARENT_EXEC_CMDS}" ]; then
+		printf "%b" "${GIT_REBASE_FIRST_PARENT_EXEC_CMDS}"
+	fi
 done
 
 sed '/^noop$/d'