diff --git a/src/plugins/help/qlitehtml/CMakeLists.txt b/src/plugins/help/qlitehtml/CMakeLists.txt
index c9bcd3326dc..b841a6bc7a9 100644
--- a/src/plugins/help/qlitehtml/CMakeLists.txt
+++ b/src/plugins/help/qlitehtml/CMakeLists.txt
@@ -4,19 +4,17 @@ project(QLiteHtml)
 
 if (EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/litehtml/CMakeLists.txt)
     set(ORIG_FPIC ${CMAKE_POSITION_INDEPENDENT_CODE})
-    set(ORIG_CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE})
-    if (CMAKE_BUILD_TYPE STREQUAL "Debug" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
-      set(CMAKE_BUILD_TYPE "RelWithDebInfo")
-    else()
-      set(CMAKE_BUILD_TYPE "Release")
-    endif()
     if (WIN32)
       set(LITEHTML_UTF8 ON)
     endif()
     set(CMAKE_POSITION_INDEPENDENT_CODE ON)
     add_subdirectory(litehtml)
-    set(CMAKE_BUILD_TYPE ${ORIG_CMAKE_BUILD_TYPE})
     set(CMAKE_POSITION_INDEPENDENT_CODE "${ORIG_FPIC}")
+    # force optimized litehtml even in debug
+    if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+      target_compile_options(gumbo PRIVATE -O2)
+      target_compile_options(litehtml PRIVATE -O2)
+    endif()
 else()
     find_package(litehtml REQUIRED)
 endif()