3 files changed, 29 insertions, 0 deletions
diff --git a/src/transformations/hgridshift.cpp b/src/transformations/hgridshift.cpp
index 3b6e366f..24da4dde 100644
--- a/src/transformations/hgridshift.cpp
+++ b/src/transformations/hgridshift.cpp
@@ -111,10 +111,19 @@ static PJ *destructor (PJ *P, int errlev) {
     return pj_default_destructor(P, errlev);
 }
 
+static void reassign_context( PJ* P, PJ_CONTEXT* ctx )
+{
+    auto Q = (struct hgridshiftData *) P->opaque;
+    for( auto& grid: Q->grids ) {
+        grid->reassign_context(ctx);
+    }
+}
+
 PJ *TRANSFORMATION(hgridshift,0) {
     auto Q = new hgridshiftData;
     P->opaque = (void *) Q;
     P->destructor = destructor;
+    P->reassign_context = reassign_context;
 
     P->fwd4d  = forward_4d;
     P->inv4d  = reverse_4d;
diff --git a/src/transformations/vgridshift.cpp b/src/transformations/vgridshift.cpp
index f35832e1..3e7a015e 100644
--- a/src/transformations/vgridshift.cpp
+++ b/src/transformations/vgridshift.cpp
@@ -142,10 +142,20 @@ static PJ *destructor (PJ *P, int errlev) {
     return pj_default_destructor(P, errlev);
 }
 
+static void reassign_context( PJ* P, PJ_CONTEXT* ctx )
+{
+    auto Q = (struct vgridshiftData *) P->opaque;
+    for( auto& grid: Q->grids ) {
+        grid->reassign_context(ctx);
+    }
+}
+
+
 PJ *TRANSFORMATION(vgridshift,0) {
     auto Q = new vgridshiftData;
     P->opaque = (void *) Q;
     P->destructor = destructor;
+    P->reassign_context = reassign_context;
 
    if (!pj_param(P->ctx, P->params, "tgrids").i) {
         proj_log_error(P, "vgridshift: +grids parameter missing.");
diff --git a/src/transformations/xyzgridshift.cpp b/src/transformations/xyzgridshift.cpp
index f23c2588..734ffc5d 100644
--- a/src/transformations/xyzgridshift.cpp
+++ b/src/transformations/xyzgridshift.cpp
@@ -270,10 +270,20 @@ static PJ *destructor (PJ *P, int errlev) {
     return pj_default_destructor(P, errlev);
 }
 
+static void reassign_context( PJ* P, PJ_CONTEXT* ctx )
+{
+    auto Q = (struct xyzgridshiftData *) P->opaque;
+    for( auto& grid: Q->grids ) {
+        grid->reassign_context(ctx);
+    }
+}
+
+
 PJ *TRANSFORMATION(xyzgridshift,0) {
     auto Q = new xyzgridshiftData;
     P->opaque = (void *) Q;
     P->destructor = destructor;
+    P->reassign_context = reassign_context;
 
     P->fwd4d  = nullptr;
     P->inv4d  = nullptr;