diff --git a/fstest/test_all/run.go b/fstest/test_all/run.go
index ea10b385d..0d12aa15c 100644
--- a/fstest/test_all/run.go
+++ b/fstest/test_all/run.go
@@ -15,6 +15,7 @@ import (
 	"path"
 	"regexp"
 	"runtime"
+	"sort"
 	"strings"
 	"sync"
 	"time"
@@ -101,6 +102,35 @@ func (r *Run) dumpOutput() {
 	log.Println("------------------------------------------------------------")
 }
 
+// This converts a slice of test names into a regexp which matches
+// them.
+func testsToRegexp(tests []string) string {
+	var split []map[string]struct{}
+	// Make a slice with maps of the used parts at each level
+	for _, test := range tests {
+		for i, name := range strings.Split(test, "/") {
+			if i >= len(split) {
+				split = append(split, make(map[string]struct{}))
+			}
+			split[i][name] = struct{}{}
+		}
+	}
+	var out []string
+	for _, level := range split {
+		var testsInLevel = []string{}
+		for name := range level {
+			testsInLevel = append(testsInLevel, name)
+		}
+		sort.Strings(testsInLevel)
+		if len(testsInLevel) > 1 {
+			out = append(out, "^("+strings.Join(testsInLevel, "|")+")$")
+		} else {
+			out = append(out, "^"+testsInLevel[0]+"$")
+		}
+	}
+	return strings.Join(out, "/")
+}
+
 var failRe = regexp.MustCompile(`(?m)^\s*--- FAIL: (Test.*?) \(`)
 
 // findFailures looks for all the tests which failed
@@ -126,7 +156,7 @@ func (r *Run) findFailures() {
 	}
 	r.failedTests = newTests
 	if len(r.failedTests) != 0 {
-		r.runFlag = "^(" + strings.Join(r.failedTests, "|") + ")$"
+		r.runFlag = testsToRegexp(r.failedTests)
 	} else {
 		r.runFlag = ""
 	}
diff --git a/fstest/test_all/run_test.go b/fstest/test_all/run_test.go
new file mode 100644
index 000000000..b51ea3313
--- /dev/null
+++ b/fstest/test_all/run_test.go
@@ -0,0 +1,181 @@
+package main
+
+import (
+	"fmt"
+	"os/exec"
+	"regexp"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTestsToRegexp(t *testing.T) {
+	for _, test := range []struct {
+		in   []string
+		want string
+	}{
+		{
+			in:   []string{},
+			want: "",
+		},
+		{
+			in:   []string{"TestOne"},
+			want: "^TestOne$",
+		},
+		{
+			in:   []string{"TestOne", "TestTwo"},
+			want: "^(TestOne|TestTwo)$",
+		},
+		{
+			in:   []string{"TestOne", "TestTwo", "TestThree"},
+			want: "^(TestOne|TestThree|TestTwo)$",
+		},
+		{
+			in:   []string{"TestOne/Sub1"},
+			want: "^TestOne$/^Sub1$",
+		},
+		{
+			in: []string{
+				"TestOne/Sub1",
+				"TestTwo",
+			},
+			want: "^(TestOne|TestTwo)$/^Sub1$",
+		},
+		{
+			in: []string{
+				"TestOne/Sub1",
+				"TestOne/Sub2",
+				"TestTwo",
+			},
+			want: "^(TestOne|TestTwo)$/^(Sub1|Sub2)$",
+		},
+		{
+			in: []string{
+				"TestOne/Sub1",
+				"TestOne/Sub2/SubSub1",
+				"TestTwo",
+			},
+			want: "^(TestOne|TestTwo)$/^(Sub1|Sub2)$/^SubSub1$",
+		},
+		{
+			in: []string{
+				"TestTests/A1",
+				"TestTests/B/B1",
+				"TestTests/C/C3/C31",
+			},
+			want: "^TestTests$/^(A1|B|C)$/^(B1|C3)$/^C31$",
+		},
+	} {
+		got := testsToRegexp(test.in)
+		assert.Equal(t, test.want, got, fmt.Sprintf("in=%v want=%q got=%q", test.in, test.want, got))
+	}
+}
+
+var runRe = regexp.MustCompile(`(?m)^\s*=== RUN\s*(Test.*?)\s*$`)
+
+// Test the regexp work with the -run flag in actually selecting the right tests
+func TestTestsToRegexpLive(t *testing.T) {
+	for _, test := range []struct {
+		in   []string
+		want []string
+	}{
+		{
+			in: []string{
+				"TestTests/A1",
+				"TestTests/C/C3",
+			},
+			want: []string{
+				"TestTests",
+				"TestTests/A1",
+				"TestTests/C",
+				"TestTests/C/C3",
+				"TestTests/C/C3/C31",
+				"TestTests/C/C3/C32",
+			},
+		},
+		{
+			in: []string{
+				"TestTests",
+				"TestTests/A1",
+				"TestTests/B",
+				"TestTests/B/B1",
+				"TestTests/C",
+			},
+			want: []string{
+				"TestTests",
+				"TestTests/A1",
+				"TestTests/B",
+				"TestTests/B/B1",
+				"TestTests/C",
+				// FIXME there doesn't seem to be a way to select a non-terminal test
+				// and all of its subtests if there is a longer path (in this case B/B1)
+				// "TestTests/C/C1",
+				// "TestTests/C/C2",
+				// "TestTests/C/C3",
+				// "TestTests/C/C3/C31",
+				// "TestTests/C/C3/C32",
+			},
+		},
+		{
+			in: []string{
+				"TestTests/A1",
+				"TestTests/B/B1",
+				"TestTests/C/C3/C31",
+			},
+			want: []string{
+				"TestTests",
+				"TestTests/A1",
+				"TestTests/B",
+				"TestTests/B/B1",
+				"TestTests/C",
+				"TestTests/C/C3",
+				"TestTests/C/C3/C31",
+			},
+		},
+		{
+			in: []string{
+				"TestTests/B/B1",
+				"TestTests/C/C3/C31",
+			},
+			want: []string{
+				"TestTests",
+				"TestTests/B",
+				"TestTests/B/B1",
+				"TestTests/C",
+				"TestTests/C/C3",
+				"TestTests/C/C3/C31",
+			},
+		},
+	} {
+		runRegexp := testsToRegexp(test.in)
+		cmd := exec.Command("go", "test", "-v", "-run", runRegexp)
+		out, err := cmd.CombinedOutput()
+		require.NoError(t, err)
+		var got []string
+		for _, match := range runRe.FindAllSubmatch(out, -1) {
+			got = append(got, string(match[1]))
+		}
+		assert.Equal(t, test.want, got, fmt.Sprintf("in=%v want=%v got=%v, runRegexp=%q", test.in, test.want, got, runRegexp))
+	}
+}
+
+var nilTest = func(t *testing.T) {}
+
+// Nested tests for TestTestsToRegexpLive to run
+func TestTests(t *testing.T) {
+	t.Run("A1", nilTest)
+	t.Run("A2", nilTest)
+	t.Run("B", func(t *testing.T) {
+		t.Run("B1", nilTest)
+		t.Run("B2", nilTest)
+	})
+	t.Run("C", func(t *testing.T) {
+		t.Run("C1", nilTest)
+		t.Run("C2", nilTest)
+		t.Run("C3", func(t *testing.T) {
+			t.Run("C31", nilTest)
+			t.Run("C32", nilTest)
+		})
+	})
+}