diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9ab8e7ad..9416d016 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -150,7 +150,7 @@ macro(set_compiler_flags targetName)
   endif()
 
   # Enable -Werror
-  if(NOT MSVC AND NOT ${PROJECT_NAME}_QT6 AND ${PROJECT_NAME}_WERROR)
+  if(NOT MSVC AND ${PROJECT_NAME}_WERROR)
     target_compile_options(${targetName} PRIVATE -Werror -Wno-error=deprecated-declarations)
   endif()
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4a20778f..ed398023 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -233,7 +233,12 @@ else()
 endif()
 
 if(CMAKE_COMPILER_IS_GNUCXX OR IS_CLANG_BUILD)
-  target_compile_options(kddockwidgets PRIVATE -Wshadow -Wconversion -fvisibility=hidden)
+  target_compile_options(kddockwidgets PRIVATE -Wshadow -fvisibility=hidden)
+
+  # Disable -Wconversion for Qt6. The qsizetype to int conversions are harmless
+  if (NOT ${PROJECT_NAME}_QT6)
+    target_compile_options(kddockwidgets PRIVATE -Wconversion)
+  endif()
 
   if(IS_CLANG_BUILD)
     target_compile_options(kddockwidgets PRIVATE -Wweak-vtables)