diff --git a/CMakeLists.txt b/CMakeLists.txt
index 278a7f0..68bf7a1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION "3.14" )
 
-project(FORWARDDIFF LANGUAGES Fortran VERSION "0.1.0")
+project(FORWARDDIFF LANGUAGES Fortran VERSION "0.1.1")
 set(CMAKE_Fortran_MODULE_DIRECTORY "${CMAKE_BINARY_DIR}/modules")
 
 add_subdirectory(src)
diff --git a/src/forwarddiff_derivative.f90 b/src/forwarddiff_derivative.f90
index 87dd584..cff38b5 100644
--- a/src/forwarddiff_derivative.f90
+++ b/src/forwarddiff_derivative.f90
@@ -17,14 +17,14 @@ function derivative_sig(x) result(res)
 
     function gradient_sig(x) result(res)
       import :: dual
-      type(dual), intent(in) :: x(:)
+      type(dual), target, intent(in) :: x(:)
       type(dual) :: res
     end function
 
     subroutine jacobian_sig(x, f)
       import :: dual
-      type(dual), intent(in) :: x(:)
-      type(dual), intent(out) :: f(:)
+      type(dual), target, intent(in) :: x(:)
+      type(dual), target, intent(out) :: f(:)
     end subroutine
   end interface
 
@@ -46,7 +46,7 @@ subroutine gradient(fcn, x, f, dfdx, err)
     real(wp), intent(in) :: x(:)
     real(wp), intent(out) :: f
     real(wp), intent(out) :: dfdx(:)
-    character(:), allocatable :: err
+    character(:), allocatable, intent(out) :: err
 
     type(dual) :: xx(size(x))
     type(dual) :: ff
@@ -87,7 +87,7 @@ subroutine jacobian(fcn, x, f, dfdx, jt, bandwidth, blocksize, err)
     integer, optional, intent(in) :: jt
     integer, optional, intent(in) :: bandwidth
     integer, optional, intent(in) :: blocksize
-    character(:), allocatable :: err
+    character(:), allocatable, intent(out) :: err
 
     integer :: jt_
 
@@ -130,7 +130,7 @@ subroutine jacobian_dense(fcn, x, f, dfdx, err)
     real(wp), intent(in) :: x(:)
     real(wp), intent(out) :: f(:)
     real(wp), intent(out) :: dfdx(:,:)
-    character(:), allocatable :: err
+    character(:), allocatable, intent(out) :: err
 
     type(dual) :: xx(size(x))
     type(dual) :: ff(size(x))
@@ -176,7 +176,7 @@ subroutine jacobian_banded(fcn, x, f, dfdx, bandwidth, err)
     real(wp), intent(out) :: f(:)
     real(wp), intent(out) :: dfdx(:,:)
     integer, intent(in) :: bandwidth
-    character(:), allocatable :: err
+    character(:), allocatable, intent(out) :: err
 
     type(dual) :: xx(size(x))
     type(dual) :: ff(size(x))
@@ -266,7 +266,7 @@ subroutine jacobian_blockdiagonal(fcn, x, f, dfdx, blocksize, err)
     real(wp), intent(out) :: f(:)
     real(wp), intent(out) :: dfdx(:,:)
     integer, intent(in) :: blocksize
-    character(:), allocatable :: err
+    character(:), allocatable, intent(out) :: err
 
     type(dual) :: xx(size(x))
     type(dual) :: ff(size(x))
diff --git a/test/fypp_example.fypp b/test/fypp_example.fypp
index 775f920..9fa1b81 100644
--- a/test/fypp_example.fypp
+++ b/test/fypp_example.fypp
@@ -32,8 +32,8 @@ contains
     #:if NAME == 'dual'
     use forwarddiff
     #:endif
-    ${TYPE1}$, intent(in) :: u(:)
-    ${TYPE1}$, intent(out) :: du(:)
+    ${TYPE1}$, target, intent(in) :: u(:)
+    ${TYPE1}$, target, intent(out) :: du(:)
 
     ${TYPE1}$ :: tmp1, tmp2
 
diff --git a/test/test_forwarddiff.f90 b/test/test_forwarddiff.f90
index ecfb14d..eec243b 100644
--- a/test/test_forwarddiff.f90
+++ b/test/test_forwarddiff.f90
@@ -91,14 +91,14 @@ function func_intrinsics2(x) result(res)
 
   function func_grad1(x) result(res)
     use forwarddiff
-    type(dual), intent(in) :: x(:)
+    type(dual), target, intent(in) :: x(:)
     type(dual) :: res
     res = x(1)*x(1)*x(2) + x(1) + x(2)
   end function
 
   function func_grad2(x) result(res)
     use forwarddiff
-    type(dual), intent(in) :: x(:)
+    type(dual), target, intent(in) :: x(:)
     type(dual) :: res
     res = sum(x*3.14_wp)
   end function
@@ -132,8 +132,8 @@ subroutine test_jacobian()
 
   subroutine rhs_rober_dual(u, du)
     use forwarddiff
-    type(dual), intent(in) :: u(:)
-    type(dual), intent(out) :: du(:)
+    type(dual), target, intent(in) :: u(:)
+    type(dual), target, intent(out) :: du(:)
 
     real(wp), parameter :: k1 = 0.04_wp, &
                            k2 = 3.0e7_wp, &
@@ -146,8 +146,8 @@ subroutine rhs_rober_dual(u, du)
   end subroutine
 
   subroutine rhs_rober(u, du)
-    real(wp), intent(in) :: u(:)
-    real(wp), intent(out) :: du(:)
+    real(wp), target, intent(in) :: u(:)
+    real(wp), target, intent(out) :: du(:)
 
     real(wp), parameter :: k1 = 0.04_wp, &
                            k2 = 3.0e7_wp, &
diff --git a/test/test_sparse.f90 b/test/test_sparse.f90
index a3b2f02..2a7aabb 100644
--- a/test/test_sparse.f90
+++ b/test/test_sparse.f90
@@ -49,8 +49,8 @@ subroutine test_banded()
 
   subroutine rhs_banded_dual(u, du)
     use forwarddiff
-    type(dual), intent(in) :: u(:)
-    type(dual), intent(out) :: du(:)
+    type(dual), target, intent(in) :: u(:)
+    type(dual), target, intent(out) :: du(:)
     integer :: i
 
     du(1) = 3.0_wp*u(2) - u(1)
@@ -139,8 +139,8 @@ subroutine test_blockdiagonal2()
 
   subroutine rhs_blocked1_dual(u, du)
     use forwarddiff
-    type(dual), intent(in) :: u(:)
-    type(dual), intent(out) :: du(:)
+    type(dual), target, intent(in) :: u(:)
+    type(dual), target, intent(out) :: du(:)
     integer :: i
 
     du(1) = u(1) + u(2)*u(1)
@@ -156,8 +156,8 @@ subroutine rhs_blocked1_dual(u, du)
 
   subroutine rhs_blocked2_dual(u, du)
     use forwarddiff
-    type(dual), intent(in) :: u(:)
-    type(dual), intent(out) :: du(:)
+    type(dual), target, intent(in) :: u(:)
+    type(dual), target, intent(out) :: du(:)
     integer :: i
 
     du(1) = u(1) + u(2)*u(1)