diff --git a/contrib/fuzz/oss_fuzz_build.sh b/contrib/fuzz/oss_fuzz_build.sh
index 6b86dcfc1..a0c2eb253 100755
--- a/contrib/fuzz/oss_fuzz_build.sh
+++ b/contrib/fuzz/oss_fuzz_build.sh
@@ -90,11 +90,4 @@ sed -i 's/\/run\/containerd-test/\/tmp\/containerd-test/g' $SRC/containerd/integ
 
 cd integration/client
 
-# Rename all *_test.go to *_test_fuzz.go to use their declarations:
-for i in $( ls *_test.go ); do mv $i ./${i%.*}_fuzz.go; done
-
-# Remove windows test to avoid double declarations:
-rm ./client_windows_test_fuzz.go
-rm ./helpers_windows_test_fuzz.go
-
 compile_fuzzers '^func FuzzInteg.*data' compile_go_fuzzer vendor
diff --git a/integration/client/client.go b/integration/client/client.go
new file mode 100644
index 000000000..4cb51534d
--- /dev/null
+++ b/integration/client/client.go
@@ -0,0 +1,74 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package client
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/defaults"
+	"github.com/containerd/containerd/log/logtest"
+	"github.com/containerd/containerd/namespaces"
+)
+
+const (
+	testNamespace = "testing"
+)
+
+var (
+	address           string
+	ctrdStdioFilePath string
+	testSnapshotter   = containerd.DefaultSnapshotter
+	ctrd              = &daemon{}
+)
+
+func init() {
+	flag.StringVar(&address, "address", defaults.DefaultAddress, "The address to the containerd socket for use in the tests")
+}
+
+func testContext(t testing.TB) (context.Context, context.CancelFunc) {
+	ctx, cancel := context.WithCancel(context.Background())
+	ctx = namespaces.WithNamespace(ctx, testNamespace)
+	if t != nil {
+		ctx = logtest.WithT(ctx, t)
+	}
+	return ctx, cancel
+}
+
+func createShimDebugConfig() string {
+	f, err := os.CreateTemp("", "containerd-config-")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to create config file: %s\n", err)
+		os.Exit(1)
+	}
+	defer f.Close()
+	if _, err := f.WriteString("version = 2\n"); err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to write to config file %s: %s\n", f.Name(), err)
+		os.Exit(1)
+	}
+
+	if _, err := f.WriteString("[plugins.\"io.containerd.runtime.v1.linux\"]\n\tshim_debug = true\n"); err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to write to config file %s: %s\n", f.Name(), err)
+		os.Exit(1)
+	}
+
+	return f.Name()
+}
diff --git a/integration/client/client_test.go b/integration/client/client_test.go
index 35d4278b3..991b9e120 100644
--- a/integration/client/client_test.go
+++ b/integration/client/client_test.go
@@ -33,7 +33,6 @@ import (
 	imagelist "github.com/containerd/containerd/integration/images"
 	"github.com/containerd/containerd/leases"
 	"github.com/containerd/containerd/log"
-	"github.com/containerd/containerd/log/logtest"
 	"github.com/containerd/containerd/namespaces"
 	"github.com/containerd/containerd/pkg/testutil"
 	"github.com/containerd/containerd/platforms"
@@ -45,32 +44,16 @@ import (
 )
 
 var (
-	address           string
-	noDaemon          bool
-	noCriu            bool
-	supportsCriu      bool
-	testNamespace     = "testing"
-	testSnapshotter   = DefaultSnapshotter
-	ctrdStdioFilePath string
-
-	ctrd = &daemon{}
+	noDaemon     bool
+	noCriu       bool
+	supportsCriu bool
 )
 
 func init() {
-	flag.StringVar(&address, "address", defaultAddress, "The address to the containerd socket for use in the tests")
 	flag.BoolVar(&noDaemon, "no-daemon", false, "Do not start a dedicated daemon for the tests")
 	flag.BoolVar(&noCriu, "no-criu", false, "Do not run the checkpoint tests")
 }
 
-func testContext(t testing.TB) (context.Context, context.CancelFunc) {
-	ctx, cancel := context.WithCancel(context.Background())
-	ctx = namespaces.WithNamespace(ctx, testNamespace)
-	if t != nil {
-		ctx = logtest.WithT(ctx, t)
-	}
-	return ctx, cancel
-}
-
 func TestMain(m *testing.M) {
 	flag.Parse()
 	if testing.Short() {
@@ -507,26 +490,6 @@ func TestClientReconnect(t *testing.T) {
 	}
 }
 
-func createShimDebugConfig() string {
-	f, err := os.CreateTemp("", "containerd-config-")
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to create config file: %s\n", err)
-		os.Exit(1)
-	}
-	defer f.Close()
-	if _, err := f.WriteString("version = 2\n"); err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to write to config file %s: %s\n", f.Name(), err)
-		os.Exit(1)
-	}
-
-	if _, err := f.WriteString("[plugins.\"io.containerd.runtime.v1.linux\"]\n\tshim_debug = true\n"); err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to write to config file %s: %s\n", f.Name(), err)
-		os.Exit(1)
-	}
-
-	return f.Name()
-}
-
 func TestDefaultRuntimeWithNamespaceLabels(t *testing.T) {
 	client, err := newClient(t, address)
 	if err != nil {
diff --git a/integration/client/client_unix.go b/integration/client/client_unix.go
new file mode 100644
index 000000000..de83ea76b
--- /dev/null
+++ b/integration/client/client_unix.go
@@ -0,0 +1,26 @@
+//go:build !windows
+// +build !windows
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package client
+
+const (
+	defaultRoot    = "/var/lib/containerd-test"
+	defaultState   = "/run/containerd-test"
+	defaultAddress = "/run/containerd-test/containerd.sock"
+)
diff --git a/integration/client/client_unix_test.go b/integration/client/client_unix_test.go
index 621f4e17a..ba24f4ae1 100644
--- a/integration/client/client_unix_test.go
+++ b/integration/client/client_unix_test.go
@@ -27,12 +27,6 @@ import (
 	"github.com/containerd/containerd/platforms"
 )
 
-const (
-	defaultRoot    = "/var/lib/containerd-test"
-	defaultState   = "/run/containerd-test"
-	defaultAddress = "/run/containerd-test/containerd.sock"
-)
-
 var (
 	testImage             = images.Get(images.BusyBox)
 	testMultiLayeredImage = images.Get(images.VolumeCopyUp)
diff --git a/integration/client/daemon_test.go b/integration/client/daemon.go
similarity index 100%
rename from integration/client/daemon_test.go
rename to integration/client/daemon.go