diff --git a/tests/defaults/ctlsock_test.go b/tests/defaults/ctlsock_test.go
index 212ded4..b987bf6 100644
--- a/tests/defaults/ctlsock_test.go
+++ b/tests/defaults/ctlsock_test.go
@@ -4,7 +4,6 @@ import (
 	"os"
 	"syscall"
 	"testing"
-	"time"
 
 	"github.com/rfjakob/gocryptfs/internal/ctlsock"
 	"github.com/rfjakob/gocryptfs/tests/test_helpers"
@@ -38,9 +37,6 @@ func TestCtlSock(t *testing.T) {
 			t.Errorf("We should get a warning about non-canonical paths here")
 		}
 	}
-	// Give the running gocryptfs process a little bit of time to close lingering
-	// sockets. Avoid triggering the FD leak detector.
-	time.Sleep(1 * time.Millisecond)
 }
 
 func TestCtlSockDecrypt(t *testing.T) {
@@ -91,9 +87,6 @@ func TestCtlSockDecrypt(t *testing.T) {
 			t.Errorf("want=%q got=%q", p, response.Result)
 		}
 	}
-	// Give the running gocryptfs process a little bit of time to close lingering
-	// sockets. Avoid triggering the FD leak detector.
-	time.Sleep(1 * time.Millisecond)
 }
 
 func TestCtlSockDecryptCrash(t *testing.T) {
diff --git a/tests/reverse/ctlsock_test.go b/tests/reverse/ctlsock_test.go
index 6991f4f..6ccc724 100644
--- a/tests/reverse/ctlsock_test.go
+++ b/tests/reverse/ctlsock_test.go
@@ -4,7 +4,6 @@ import (
 	"io/ioutil"
 	"syscall"
 	"testing"
-	"time"
 
 	"github.com/rfjakob/gocryptfs/internal/ctlsock"
 	"github.com/rfjakob/gocryptfs/tests/test_helpers"
@@ -68,9 +67,6 @@ func TestCtlSockPathOps(t *testing.T) {
 	if response.ErrNo != int32(syscall.ENOENT) {
 		t.Errorf("File should not exist: ErrNo=%d ErrText=%s", response.ErrNo, response.ErrText)
 	}
-	// Give the running gocryptfs process a little bit of time to close lingering
-	// sockets. Avoid triggering the FD leak detector.
-	time.Sleep(1 * time.Millisecond)
 }
 
 // We should not panic when somebody feeds requests that make no sense
@@ -89,7 +85,4 @@ func TestCtlSockCrash(t *testing.T) {
 	// Try to crash it
 	req := ctlsock.RequestStruct{DecryptPath: "gocryptfs.longname.XXX_TestCtlSockCrash_XXX.name"}
 	test_helpers.QueryCtlSock(t, sock, req)
-	// Give the running gocryptfs process a little bit of time to close lingering
-	// sockets. Avoid triggering the FD leak detector.
-	time.Sleep(1 * time.Millisecond)
 }
diff --git a/tests/reverse/exclude_test.go b/tests/reverse/exclude_test.go
index c1b2180..aaecd65 100644
--- a/tests/reverse/exclude_test.go
+++ b/tests/reverse/exclude_test.go
@@ -3,7 +3,6 @@ package reverse_test
 import (
 	"io/ioutil"
 	"testing"
-	"time"
 
 	"github.com/rfjakob/gocryptfs/internal/ctlsock"
 	"github.com/rfjakob/gocryptfs/tests/test_helpers"
@@ -102,9 +101,6 @@ func testExclude(t *testing.T, flag string) {
 			t.Errorf("File %q / %q is hidden, but should be visible", pOk[i], v)
 		}
 	}
-	// Give the running gocryptfs process a little bit of time to close lingering
-	// sockets. Avoid triggering the FD leak detector.
-	time.Sleep(1 * time.Millisecond)
 }
 
 func TestExclude(t *testing.T) {
diff --git a/tests/test_helpers/mount_unmount.go b/tests/test_helpers/mount_unmount.go
index 1142666..cce763a 100644
--- a/tests/test_helpers/mount_unmount.go
+++ b/tests/test_helpers/mount_unmount.go
@@ -141,14 +141,22 @@ func UnmountErr(dir string) (err error) {
 	for i := 1; i <= max; i++ {
 		if pid > 0 {
 			fdsNow = ListFds(pid)
+			if len(fdsNow) > len(fds) {
+				// File close on FUSE is asynchronous, closing a socket
+				// when testing -ctlsock as well. Wait one extra millisecond
+				// and hope that all close commands get through to the gocryptfs
+				// process.
+				time.Sleep(1 * time.Millisecond)
+				fdsNow = ListFds(pid)
+			}
 		}
 		cmd := exec.Command(UnmountScript, "-u", dir)
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
 		err = cmd.Run()
 		if err == nil {
-			if pid > 0 && len(fdsNow) > len(fds) {
-				fmt.Printf("FD leak? Details:\nold=%v \nnew=%v\n", fds, fdsNow)
+			if len(fdsNow) > len(fds) {
+				return fmt.Errorf("FD leak? pid=%d dir=%q, fds:\nold=%v \nnew=%v\n", pid, dir, fds, fdsNow)
 			}
 			return nil
 		}