diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index c26a200a6c..dcc3401b5a 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -846,6 +846,71 @@ add_exec_commands () {
 	mv "$1.new" "$1"
 }
 
+# Check if the SHA-1 passed as an argument is a
+# correct one, if not then print $2 in "$todo".badsha
+# $1: the SHA-1 to test
+# $2: the line to display if incorrect SHA-1
+check_commit_sha () {
+	badsha=0
+	if test -z $1
+	then
+		badsha=1
+	else
+		sha1_verif="$(git rev-parse --verify --quiet $1^{commit})"
+		if test -z $sha1_verif
+		then
+			badsha=1
+		fi
+	fi
+
+	if test $badsha -ne 0
+	then
+		warn "Warning: the SHA-1 is missing or isn't" \
+			"a commit in the following line:"
+		warn " - $2"
+		warn
+	fi
+
+	return $badsha
+}
+
+# prints the bad commits and bad commands
+# from the todolist in stdin
+check_bad_cmd_and_sha () {
+	retval=0
+	git stripspace --strip-comments |
+	(
+		while read -r line
+		do
+			IFS=' '
+			set -- $line
+			command=$1
+			sha1=$2
+
+			case $command in
+			''|noop|x|"exec")
+				# Doesn't expect a SHA-1
+				;;
+			pick|p|drop|d|reword|r|edit|e|squash|s|fixup|f)
+				if ! check_commit_sha $sha1 "$line"
+				then
+					retval=1
+				fi
+				;;
+			*)
+				warn "Warning: the command isn't recognized" \
+					"in the following line:"
+				warn " - $line"
+				warn
+				retval=1
+				;;
+			esac
+		done
+
+		return $retval
+	)
+}
+
 # Print the list of the SHA-1 of the commits
 # from stdin to stdout
 todo_list_to_sha_list () {
@@ -887,6 +952,8 @@ get_missing_commit_check_level () {
 
 # Check if the user dropped some commits by mistake
 # Behaviour determined by rebase.missingCommitsCheck.
+# Check if there is an unrecognized command or a
+# bad SHA-1 in a command.
 check_todo_list () {
 	raise_error=f
 
@@ -935,6 +1002,11 @@ check_todo_list () {
 		;;
 	esac
 
+	if ! check_bad_cmd_and_sha <"$todo"
+	then
+		raise_error=t
+	fi
+
 	if test $raise_error = t
 	then
 		# Checkout before the first commit of the
diff --git a/t/lib-rebase.sh b/t/lib-rebase.sh
index fdbc9007d0..9a96e1566d 100644
--- a/t/lib-rebase.sh
+++ b/t/lib-rebase.sh
@@ -54,6 +54,11 @@ set_fake_editor () {
 			echo '# comment' >> "$1";;
 		">")
 			echo >> "$1";;
+		bad)
+			action="badcmd";;
+		fakesha)
+			echo "$action XXXXXXX False commit" >> "$1"
+			action=pick;;
 		*)
 			sed -n "${line}s/^pick/$action/p" < "$1".tmp >> "$1"
 			action=pick;;
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index cfa741018d..ebdab4b95d 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1186,4 +1186,43 @@ test_expect_success 'rebase -i respects rebase.missingCommitsCheck = error' '
 	test B = $(git cat-file commit HEAD^ | sed -ne \$p)
 '
 
+cat >expect <<EOF
+Warning: the command isn't recognized in the following line:
+ - badcmd $(git rev-list --oneline -1 master~1)
+
+You can fix this with 'git rebase --edit-todo'.
+Or you can abort the rebase with 'git rebase --abort'.
+EOF
+
+test_expect_success 'static check of bad command' '
+	rebase_setup_and_clean bad-cmd &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 2 3 bad 4 5" \
+		git rebase -i --root 2>actual &&
+	test_cmp expect actual &&
+	FAKE_LINES="1 2 3 drop 4 5" git rebase --edit-todo &&
+	git rebase --continue &&
+	test E = $(git cat-file commit HEAD | sed -ne \$p) &&
+	test C = $(git cat-file commit HEAD^ | sed -ne \$p)
+'
+
+cat >expect <<EOF
+Warning: the SHA-1 is missing or isn't a commit in the following line:
+ - edit XXXXXXX False commit
+
+You can fix this with 'git rebase --edit-todo'.
+Or you can abort the rebase with 'git rebase --abort'.
+EOF
+
+test_expect_success 'static check of bad SHA-1' '
+	rebase_setup_and_clean bad-sha &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES="1 2 edit fakesha 3 4 5 #" \
+		git rebase -i --root 2>actual &&
+	test_cmp expect actual &&
+	FAKE_LINES="1 2 4 5 6" git rebase --edit-todo &&
+	git rebase --continue &&
+	test E = $(git cat-file commit HEAD | sed -ne \$p)
+'
+
 test_done