diff --git a/scripts/cmake/Find.cmake b/scripts/cmake/Find.cmake
index 5a60cc890bc31fc3506ab2937a1021cc96a474e2..215282d91236858c3540d0020054f60d64b7d166 100644
--- a/scripts/cmake/Find.cmake
+++ b/scripts/cmake/Find.cmake
@@ -135,7 +135,7 @@ IF(OGS_USE_PETSC)
     SET(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${PROJECT_SOURCE_DIR}/scripts/cmake/findPETSC")
     FIND_PACKAGE(PETSc REQUIRED)
 
-    INCLUDE_DIRECTORIES(${PETSC_INCLUDES})
+    INCLUDE_DIRECTORIES(SYSTEM ${PETSC_INCLUDES})
 
     ADD_DEFINITIONS(-DPETSC_VERSION_NUMBER=PETSC_VERSION_MAJOR*1000+PETSC_VERSION_MINOR*10)