diff --git a/src/xSTIR/cSTIR/cstir.cpp b/src/xSTIR/cSTIR/cstir.cpp
index ab6f515b5..c7cbb4956 100644
--- a/src/xSTIR/cSTIR/cstir.cpp
+++ b/src/xSTIR/cSTIR/cstir.cpp
@@ -183,7 +183,8 @@ void* cSTIR_newObject(const char* name)
 		if (sirf::iequals(name, "LogcoshPrior"))
 			return NEW_OBJECT_HANDLE(LogPrior3DF);
 		if (sirf::iequals(name, "RelativeDifferencePrior"))
-			return NEW_OBJECT_HANDLE(RDPrior3DF);
+			return NEW_OBJECT_HANDLE(xSTIR_RelativeDifferencePrior3DF);
+			//return NEW_OBJECT_HANDLE(RDPrior3DF);
 #ifdef STIR_WITH_CUDA
 		if (sirf::iequals(name, "CudaRelativeDifferencePrior"))
 			return NEW_OBJECT_HANDLE(CudaRDPrior3DF);
diff --git a/src/xSTIR/cSTIR/cstir_p.cpp b/src/xSTIR/cSTIR/cstir_p.cpp
index e08f3b9e9..532b46597 100644
--- a/src/xSTIR/cSTIR/cstir_p.cpp
+++ b/src/xSTIR/cSTIR/cstir_p.cpp
@@ -707,10 +707,12 @@ void*
 sirf::cSTIR_setRelativeDifferencePriorParameter
 (DataHandle* hp, const char* name, const DataHandle* hv)
 {
-        auto& prior = objectFromHandle<stir::RelativeDifferencePrior<float>>(hp);
+        //auto& prior = objectFromHandle<stir::RelativeDifferencePrior<float>>(hp);
+	auto& prior = objectFromHandle<xSTIR_RelativeDifferencePrior3DF>(hp);
 	if (sirf::iequals(name, "only_2D")) {
-		auto& xrdp = objectFromHandle<xSTIR_RelativeDifferencePrior3DF>(hp);
-		xrdp.only2D(dataFromHandle<int>((void*)hv));
+		//auto& xrdp = objectFromHandle<xSTIR_RelativeDifferencePrior3DF>(hp);
+		//xrdp.only2D(dataFromHandle<int>((void*)hv));
+		prior.only2D(dataFromHandle<int>((void*)hv));
         }
 	else if (sirf::iequals(name, "kappa")) {
 		auto& id = objectFromHandle<STIRImageData>(hv);
@@ -729,7 +731,8 @@ void*
 sirf::cSTIR_RelativeDifferencePriorParameter
 (DataHandle* hp, const char* name)
 {
-	auto& prior = objectFromHandle<stir::RelativeDifferencePrior<float>>(hp);
+	//auto& prior = objectFromHandle<stir::RelativeDifferencePrior<float>>(hp);
+	auto& prior = objectFromHandle<xSTIR_RelativeDifferencePrior3DF>(hp);
 	if (sirf::iequals(name, "kappa")) {
 		auto sptr_im = std::make_shared<STIRImageData>(*prior.get_kappa_sptr());
 		return newObjectHandle(sptr_im);
diff --git a/src/xSTIR/cSTIR/include/sirf/STIR/stir_x.h b/src/xSTIR/cSTIR/include/sirf/STIR/stir_x.h
index a122b73ed..68d464b31 100644
--- a/src/xSTIR/cSTIR/include/sirf/STIR/stir_x.h
+++ b/src/xSTIR/cSTIR/include/sirf/STIR/stir_x.h
@@ -39,6 +39,8 @@ limitations under the License.
 #include "sirf/common/iequals.h"
 #include "sirf/common/JacobiCG.h"
 #include "sirf/STIR/stir_data_containers.h"
+
+#include "stir/recon_buildblock/GibbsRelativeDifferencePenalty.h"
 #include "stir/recon_buildblock/PoissonLogLikelihoodWithLinearModelForMeanAndProjData.h"
 #include "stir/recon_buildblock/PoissonLogLikelihoodWithLinearModelForMeanAndListModeDataWithProjMatrixByBin.h"
 #include "stir/GeneralisedPoissonNoiseGenerator.h"
@@ -1143,7 +1145,8 @@ The actual algorithm is described in
 		}
 	};
 
-	class xSTIR_RelativeDifferencePrior3DF : public stir::RelativeDifferencePrior < float > {
+	class xSTIR_RelativeDifferencePrior3DF : public stir::GibbsRelativeDifferencePenalty<float> {
+	//class xSTIR_RelativeDifferencePrior3DF : public stir::RelativeDifferencePrior<float> {
 	public:
 		void only2D(int only) {
 			only_2D = only != 0;