diff --git a/node_modules/app-builder-lib/templates/nsis/include/installer.nsh b/node_modules/app-builder-lib/templates/nsis/include/installer.nsh
index 34e91df..73bfffc 100644
--- a/node_modules/app-builder-lib/templates/nsis/include/installer.nsh
+++ b/node_modules/app-builder-lib/templates/nsis/include/installer.nsh
@@ -90,7 +90,13 @@
       ${if} $installMode == "all"
         SetShellVarContext current
       ${endif}
-      !insertmacro copyFile "$EXEPATH" "$LOCALAPPDATA\${APP_INSTALLER_STORE_FILE}"
+      # SIGNAL CHANGE START
+      # This file is needed for electron-builder's native incremental updates,
+      # but we have our own system so no need to place it. Clean it up instead.
+      #
+      # !insertmacro copyFile "$EXEPATH" "$LOCALAPPDATA\${APP_INSTALLER_STORE_FILE}"
+      RMDir /r /REBOOTOK "$LOCALAPPDATA\signal-desktop-updater"
+      # SIGNAL CHANGE END
       ${if} $installMode == "all"
         SetShellVarContext all
       ${endif}
diff --git a/node_modules/app-builder-lib/templates/nsis/installSection.nsh b/node_modules/app-builder-lib/templates/nsis/installSection.nsh
index 053772f..a58ea8c 100644
--- a/node_modules/app-builder-lib/templates/nsis/installSection.nsh
+++ b/node_modules/app-builder-lib/templates/nsis/installSection.nsh
@@ -22,11 +22,37 @@ StrCpy $appExe "$INSTDIR\${APP_EXECUTABLE_FILENAME}"
       SpiderBanner::Show /MODERN
     !endif
 
+    # Set text (1000 is the id of text element of SpiderBanner)
     FindWindow $0 "#32770" "" $hwndparent
     FindWindow $0 "#32770" "" $hwndparent $0
-    GetDlgItem $0 $0 1000
-    SendMessage $0 ${WM_SETTEXT} 0 "STR:$(installing)"
 
+    GetDlgItem $1 $0 1000
+    SendMessage $1 ${WM_SETTEXT} 0 "STR:$(installing)"
+
+    # Set header image compatible with "ManifestDPIAware" mode.
+    !ifdef HEADER_ICO
+      # Convert 24 Dialog Units to pixels:
+      # See https://github.com/mozilla/gecko-dev/blob/8de0e699002872d969aebf1bc8407e5c839a4472/toolkit/mozapps/installer/windows/nsis/common.nsh#L8801
+
+      # rect = LPRect { .left = 0, .top = 0, .right = 24, .bottom = 0 }
+      # See https://nsis.sourceforge.io/Docs/System/System.html#faq
+      System::Call "*(i 0, i 0, i 24, i 0) p.r1"
+
+      # Call `MapDialogRect(window, &rect)`
+      System::Call `user32::MapDialogRect(p $0, p r1)`
+
+      # rect.right now contains the converted value (24du => ?px).
+      # Place `rect.right` into `r2`
+      System::Call "*$1(i, i, i.r2, i)"
+      System::Free $1
+
+      # Load image and pass `r2` as both width and height, get the image handle
+      # back to `r2` register.
+      System::Call `user32::LoadImage(i 0, t "$PLUGINSDIR\installerHeaderico.ico", i ${IMAGE_ICON}, i r2, i r2, i ${LR_LOADFROMFILE}) i.r2`
+      # 1025 is the id of the icon of SpiderBanner.
+      GetDlgItem $1 $0 1025
+      SendMessage $1 ${STM_SETIMAGE} ${IMAGE_ICON} $2
+    !endif
     StrCpy $1 $hwndparent
 		System::Call 'user32::ShutdownBlockReasonCreate(${SYSTYPE_PTR}r1, w "$(installing)")'
   ${endif}