diff --git a/cmake/Modules/LAMMPSUtils.cmake b/cmake/Modules/LAMMPSUtils.cmake
index d42f91f10e..9b42dafc44 100644
--- a/cmake/Modules/LAMMPSUtils.cmake
+++ b/cmake/Modules/LAMMPSUtils.cmake
@@ -99,8 +99,15 @@ function(check_for_autogen_files source_dir)
 endfunction()
 
 macro(pkg_depends PKG1 PKG2)
-  if(PKG_${PKG1} AND NOT (PKG_${PKG2} OR BUILD_${PKG2}))
-    message(FATAL_ERROR "The ${PKG1} package needs LAMMPS to be built with the ${PKG2} package")
+  if(DEFINED BUILD_${PKG2})
+    if(PKG_${PKG1} AND NOT BUILD_${PKG2})
+      message(FATAL_ERROR "The ${PKG1} package needs LAMMPS to be built with -D BUILD_${PKG2}=ON")
+    endif()
+  elseif(DEFINED PKG_${PKG2})
+    if(PKG_${PKG1} AND NOT PKG_${PKG2})
+      message(WARNING "The ${PKG1} package depends on the ${PKG2} package. Enabling it.")
+      set(PKG_${PKG2} ON CACHE BOOL "" FORCE)
+    endif()
   endif()
 endmacro()