diff --git a/Solver/linearSystemPETSc.h b/Solver/linearSystemPETSc.h
index a2e908a547c3c0c15a16a621c0dd1a45267784b0..9d2a528d0a1c1e9f728054f89e94eee44e975f27 100644
--- a/Solver/linearSystemPETSc.h
+++ b/Solver/linearSystemPETSc.h
@@ -42,6 +42,7 @@
 #include <vector>
 #if defined(HAVE_PETSC)
 #include "petsc.h"
+#include <petscksp.h>
 template <class scalar>
 class linearSystemPETSc : public linearSystem<scalar> {
   protected: