diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index b27344d..0aa0dfb 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -774,11 +774,11 @@
     return getComposer()->isUsingVrComposer();
 }
 
-void HWComposer::dump(String8& result) const {
+void HWComposer::dump(std::string& result) const {
     // TODO: In order to provide a dump equivalent to HWC1, we need to shadow
     // all the state going into the layers. This is probably better done in
     // Layer itself, but it's going to take a bit of work to get there.
-    result.append(mHwcDevice->dump().c_str());
+    result.append(mHwcDevice->dump());
 }
 
 std::optional<DisplayId> HWComposer::toPhysicalDisplayId(hwc2_display_t hwcDisplayId) const {
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 3f1328e..aaa6e8c 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -37,7 +37,6 @@
 namespace android {
 
 class GraphicBuffer;
-class String8;
 class TestableSurfaceFlinger;
 struct CompositionInfo;
 
@@ -161,7 +160,7 @@
     bool isUsingVrComposer() const;
 
     // for debugging ----------------------------------------------------------
-    void dump(String8& out) const;
+    void dump(std::string& out) const;
 
     Hwc2::Composer* getComposer() const { return mHwcDevice->getComposer(); }