diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
index 84d6cc021c51ac53b68a8b9fdbdd3ed0f8d9d30a..7bfb6737dfe7be46f3f29903bef844c3c2b1be11 100755
--- a/git-difftool--helper.sh
+++ b/git-difftool--helper.sh
@@ -86,6 +86,13 @@ else
 	do
 		launch_merge_tool "$1" "$2" "$5"
 		status=$?
+		if test $status -ge 126
+		then
+			# Command not found (127), not executable (126) or
+			# exited via a signal (>= 128).
+			exit $status
+		fi
+
 		if test "$status" != 0 &&
 			test "$GIT_DIFFTOOL_TRUST_EXIT_CODE" = true
 		then
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 2974900578d3f21b57d5773973344a1743e8e6e0..70a2de461af58119f507a915104ba139dd0245df 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -124,6 +124,12 @@ test_expect_success PERL 'difftool stops on error with --trust-exit-code' '
 	test_cmp expect actual
 '
 
+test_expect_success PERL 'difftool honors exit status if command not found' '
+	test_config difftool.nonexistent.cmd i-dont-exist &&
+	test_config difftool.trustExitCode false &&
+	test_must_fail git difftool -y -t nonexistent branch
+'
+
 test_expect_success PERL 'difftool honors --gui' '
 	difftool_test_setup &&
 	test_config merge.tool bogus-tool &&