diff --git a/fvn_sparse/fvn_sparse.f90 b/fvn_sparse/fvn_sparse.f90
index 2fd3f2b..a7abc81 100644
--- a/fvn_sparse/fvn_sparse.f90
+++ b/fvn_sparse/fvn_sparse.f90
@@ -11,6 +11,46 @@ interface fvn_sparse_det
     module procedure fvn_zl_sparse_det,fvn_zi_sparse_det,fvn_dl_sparse_det,fvn_di_sparse_det
 end interface fvn_sparse_det
 contains
+
+function umfpack_return_code(c)
+  implicit none
+  integer(4), intent(in) :: c
+  character(len=80) :: umfpack_return_code
+  select case(c)
+    case(0)
+      umfpack_return_code="UMFPACK_OK"
+    case(1)
+      umfpack_return_code="UMFPACK_WARNING_singular_matrix"
+    case(2)
+      umfpack_return_code="UMFPACK_WARNING_determinant_underflow"
+    case(3)
+      umfpack_return_code="UMFPACK_WARNING_determinant_overflow"
+    case(-1)
+      umfpack_return_code="UMFPACK_ERROR_out_of_memory"
+    case(-3)
+      umfpack_return_code="UMFPACK_ERROR_invalid_Numeric_object"
+    case(-4)
+      umfpack_return_code="UMFPACK_ERROR_invalid_Symbolic_object"
+    case(-5)
+      umfpack_return_code="UMFPACK_ERROR_argument_missing"
+    case(-6)
+      umfpack_return_code="UMFPACK_ERROR_n_nonpositive"
+    case(-8)
+      umfpack_return_code="UMFPACK_ERROR_invalid_matrix"
+    case(-11)
+      umfpack_return_code="UMFPACK_ERROR_different_pattern"
+    case(-13)
+      umfpack_return_code="UMFPACK_ERROR_invalid_system"
+    case(-15)
+      umfpack_return_code="UMFPACK_ERROR_invalid_permutation"
+    case(-911)
+      umfpack_return_code="UMFPACK_ERROR_internal_error"
+    case(-17)
+      umfpack_return_code="UMFPACK_ERROR_file_IO"
+    case default
+      umfpack_return_code="Unknown return code"
+  end select
+end function
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 !
 ! SPARSE RESOLUTION