diff --git a/src/gpu/VirtualFluids_GPU/Kernel/Kernels/BasicKernels/FluidFlow/Compressible/CumulantK17chimStream/CumulantK17CompChimStreamDevice.cu b/src/gpu/VirtualFluids_GPU/Kernel/Kernels/BasicKernels/FluidFlow/Compressible/CumulantK17chimStream/CumulantK17CompChimStreamDevice.cu
index 6378b691daf5cf86c5443a748d05fc2fc667a290..da37bb1e2fee675cb07410d483dac21dc84215dc 100644
--- a/src/gpu/VirtualFluids_GPU/Kernel/Kernels/BasicKernels/FluidFlow/Compressible/CumulantK17chimStream/CumulantK17CompChimStreamDevice.cu
+++ b/src/gpu/VirtualFluids_GPU/Kernel/Kernels/BasicKernels/FluidFlow/Compressible/CumulantK17chimStream/CumulantK17CompChimStreamDevice.cu
@@ -45,7 +45,7 @@ extern "C" __global__ void LB_Kernel_CumulantK17CompChimStream(
 	uint* neighborY,
 	uint* neighborZ,
 	real* distributions,
-	int size_Mat,
+	unsigned long size_Mat,
 	int level,
 	real* forces,
 	real* quadricLimiters,
diff --git a/src/gpu/VirtualFluids_GPU/Kernel/Kernels/BasicKernels/FluidFlow/Compressible/CumulantK17chimStream/CumulantK17CompChimStream_Device.cuh b/src/gpu/VirtualFluids_GPU/Kernel/Kernels/BasicKernels/FluidFlow/Compressible/CumulantK17chimStream/CumulantK17CompChimStream_Device.cuh
index 2ac08edd28561f739bb2faf701505b9f9e7217b9..035e438ccf8df70c5df43c70f0b4a5ffe160acc8 100644
--- a/src/gpu/VirtualFluids_GPU/Kernel/Kernels/BasicKernels/FluidFlow/Compressible/CumulantK17chimStream/CumulantK17CompChimStream_Device.cuh
+++ b/src/gpu/VirtualFluids_GPU/Kernel/Kernels/BasicKernels/FluidFlow/Compressible/CumulantK17chimStream/CumulantK17CompChimStream_Device.cuh
@@ -10,7 +10,7 @@ extern "C" __global__ void LB_Kernel_CumulantK17CompChimStream(
 	uint* neighborY,
 	uint* neighborZ,
 	real* distributions,
-	int size_Mat,
+	unsigned long size_Mat,
 	int level,
 	real* forces,
 	real* quadricLimiters,