diff --git a/cmake/system.cmake b/cmake/system.cmake
index c9457bc84..c47965d8e 100644
--- a/cmake/system.cmake
+++ b/cmake/system.cmake
@@ -285,6 +285,9 @@ if (NOT NOFORTRAN)
   include("${PROJECT_SOURCE_DIR}/cmake/fc.cmake")
 else ()
 set(C_LAPACK 1)
+if (INTERFACE64)
+  set (CCOMMON_OPT "${CCOMMON_OPT} -DLAPACK_ILP64")
+endif ()
 set(TIMER "NONE")
 #set(NO_LAPACKE 1)
 endif ()