diff --git a/fs_mgr/libdm/dm_test.cpp b/fs_mgr/libdm/dm_test.cpp
index 39c908db2..ed2fa8329 100644
--- a/fs_mgr/libdm/dm_test.cpp
+++ b/fs_mgr/libdm/dm_test.cpp
@@ -47,50 +47,6 @@ TEST(libdm, HasMinimumTargets) {
     ASSERT_TRUE(dm.GetTargetByName("linear", &info));
 }
 
-// Helper to ensure that device mapper devices are released.
-class TempDevice {
-  public:
-    TempDevice(const std::string& name, const DmTable& table)
-        : dm_(DeviceMapper::Instance()), name_(name), valid_(false) {
-        valid_ = dm_.CreateDevice(name, table, &path_, 5s);
-    }
-    TempDevice(TempDevice&& other) noexcept
-        : dm_(other.dm_), name_(other.name_), path_(other.path_), valid_(other.valid_) {
-        other.valid_ = false;
-    }
-    ~TempDevice() {
-        if (valid_) {
-            dm_.DeleteDevice(name_);
-        }
-    }
-    bool Destroy() {
-        if (!valid_) {
-            return false;
-        }
-        valid_ = false;
-        return dm_.DeleteDevice(name_);
-    }
-    std::string path() const { return path_; }
-    const std::string& name() const { return name_; }
-    bool valid() const { return valid_; }
-
-    TempDevice(const TempDevice&) = delete;
-    TempDevice& operator=(const TempDevice&) = delete;
-
-    TempDevice& operator=(TempDevice&& other) noexcept {
-        name_ = other.name_;
-        valid_ = other.valid_;
-        other.valid_ = false;
-        return *this;
-    }
-
-  private:
-    DeviceMapper& dm_;
-    std::string name_;
-    std::string path_;
-    bool valid_;
-};
-
 TEST(libdm, DmLinear) {
     unique_fd tmp1(CreateTempFile("file_1", 4096));
     ASSERT_GE(tmp1, 0);
diff --git a/fs_mgr/libdm/test_util.h b/fs_mgr/libdm/test_util.h
index 96b051ca2..66713641e 100644
--- a/fs_mgr/libdm/test_util.h
+++ b/fs_mgr/libdm/test_util.h
@@ -20,8 +20,12 @@
 #include <android-base/unique_fd.h>
 #include <stddef.h>
 
+#include <chrono>
 #include <string>
 
+#include <libdm/dm.h>
+#include <libdm/dm_table.h>
+
 namespace android {
 namespace dm {
 
@@ -29,6 +33,50 @@ namespace dm {
 // created with a fixed size.
 android::base::unique_fd CreateTempFile(const std::string& name, size_t size);
 
+// Helper to ensure that device mapper devices are released.
+class TempDevice {
+  public:
+    TempDevice(const std::string& name, const DmTable& table)
+        : dm_(DeviceMapper::Instance()), name_(name), valid_(false) {
+        valid_ = dm_.CreateDevice(name, table, &path_, std::chrono::seconds(5));
+    }
+    TempDevice(TempDevice&& other) noexcept
+        : dm_(other.dm_), name_(other.name_), path_(other.path_), valid_(other.valid_) {
+        other.valid_ = false;
+    }
+    ~TempDevice() {
+        if (valid_) {
+            dm_.DeleteDevice(name_);
+        }
+    }
+    bool Destroy() {
+        if (!valid_) {
+            return false;
+        }
+        valid_ = false;
+        return dm_.DeleteDevice(name_);
+    }
+    std::string path() const { return path_; }
+    const std::string& name() const { return name_; }
+    bool valid() const { return valid_; }
+
+    TempDevice(const TempDevice&) = delete;
+    TempDevice& operator=(const TempDevice&) = delete;
+
+    TempDevice& operator=(TempDevice&& other) noexcept {
+        name_ = other.name_;
+        valid_ = other.valid_;
+        other.valid_ = false;
+        return *this;
+    }
+
+  private:
+    DeviceMapper& dm_;
+    std::string name_;
+    std::string path_;
+    bool valid_;
+};
+
 }  // namespace dm
 }  // namespace android