diff --git a/cmd/nerdctl/builder_build_test.go b/cmd/nerdctl/builder_build_test.go
index 59b25d7fc42..472d93b2495 100644
--- a/cmd/nerdctl/builder_build_test.go
+++ b/cmd/nerdctl/builder_build_test.go
@@ -152,7 +152,6 @@ CMD ["cat", "/hello2"]
 }
 
 func TestBuildFromStdin(t *testing.T) {
-	t.Parallel()
 	testutil.RequiresBuild(t)
 	base := testutil.NewBase(t)
 	defer base.Cmd("builder", "prune").Run()
@@ -199,7 +198,6 @@ CMD ["echo", "nerdctl-build-test-dockerfile"]
 }
 
 func TestBuildLocal(t *testing.T) {
-	t.Parallel()
 	testutil.RequiresBuild(t)
 	base := testutil.NewBase(t)
 	if testutil.GetTarget() == testutil.Docker {
@@ -293,7 +291,6 @@ CMD echo $TEST_STRING
 }
 
 func TestBuildWithIIDFile(t *testing.T) {
-	t.Parallel()
 	testutil.RequiresBuild(t)
 	base := testutil.NewBase(t)
 	defer base.Cmd("builder", "prune").Run()
@@ -318,7 +315,6 @@ CMD ["echo", "nerdctl-build-test-string"]
 }
 
 func TestBuildWithLabels(t *testing.T) {
-	t.Parallel()
 	testutil.RequiresBuild(t)
 	base := testutil.NewBase(t)
 	defer base.Cmd("builder", "prune").Run()
@@ -547,7 +543,6 @@ func buildWithNamedBuilder(base *testutil.Base, builderName string, args ...stri
 }
 
 func TestBuildAttestation(t *testing.T) {
-	t.Parallel()
 	testutil.RequiresBuild(t)
 	base := testutil.NewBase(t)
 	builderName := testutil.Identifier(t)
diff --git a/cmd/nerdctl/container_logs_test.go b/cmd/nerdctl/container_logs_test.go
index 944b48486d2..ac036e74c52 100644
--- a/cmd/nerdctl/container_logs_test.go
+++ b/cmd/nerdctl/container_logs_test.go
@@ -209,7 +209,7 @@ func TestLogsWithForegroundContainers(t *testing.T) {
 }
 
 func TestTailFollowRotateLogs(t *testing.T) {
-	// FIXME this is flaky by nature... 5 lines is arbitrary, 2000 ms is arbitrary, and both are some sort of educated
+	// FIXME this is flaky by nature... 2 lines is arbitrary, 10000 ms is arbitrary, and both are some sort of educated
 	// guess that things will mostly always kinda work maybe...
 	// Furthermore, parallelizing will put pressure on the daemon which might be even slower in answering, increasing
 	// the risk of transient failure.
@@ -222,7 +222,7 @@ func TestTailFollowRotateLogs(t *testing.T) {
 	containerName := testutil.Identifier(t)
 
 	const sampleJSONLog = `{"log":"A\n","stream":"stdout","time":"2024-04-11T12:01:09.800288974Z"}`
-	const linesPerFile = 5
+	const linesPerFile = 2
 
 	defer base.Cmd("rm", "-f", containerName).Run()
 	base.Cmd("run", "-d", "--log-driver", "json-file",
@@ -232,7 +232,7 @@ func TestTailFollowRotateLogs(t *testing.T) {
 		"sh", "-euc", "while true; do echo A; done").AssertOK()
 
 	tailLogCmd := base.Cmd("logs", "-f", containerName)
-	tailLogCmd.Timeout = 2000 * time.Millisecond
+	tailLogCmd.Timeout = 10000 * time.Millisecond
 	tailLogs := strings.Split(strings.TrimSpace(tailLogCmd.Run().Stdout()), "\n")
 	for _, line := range tailLogs {
 		if line != "" {
diff --git a/pkg/testutil/testutil_linux.go b/pkg/testutil/testutil_linux.go
index b6573b122a5..b3628f128e0 100644
--- a/pkg/testutil/testutil_linux.go
+++ b/pkg/testutil/testutil_linux.go
@@ -124,7 +124,8 @@ func NewDelayOnceReader(wrapped io.Reader) io.Reader {
 }
 
 func (r *delayOnceReader) Read(p []byte) (int, error) {
-	r.once.Do(func() { time.Sleep(time.Second) })
+	// FIXME: this is obviously not exact science. At 1 second, it will fail regularly on the CI under load.
+	r.once.Do(func() { time.Sleep(2 * time.Second) })
 	n, err := r.wrapped.Read(p)
 	if errors.Is(err, io.EOF) {
 		time.Sleep(time.Second)