diff --git a/src/gpu/assemble_MPI_vector_cuda.cu b/src/gpu/assemble_MPI_vector_cuda.cu
index 360717b55..c8474d96f 100644
--- a/src/gpu/assemble_MPI_vector_cuda.cu
+++ b/src/gpu/assemble_MPI_vector_cuda.cu
@@ -28,6 +28,7 @@
 */
 
 #include "mesh_constants_gpu.h"
+#include <string.h>
 
 /* ----------------------------------------------------------------------------------------------- */
 
diff --git a/src/gpu/lts_assembly_mpi_cuda.cu b/src/gpu/lts_assembly_mpi_cuda.cu
index 83aab4f65..515dcfbdb 100644
--- a/src/gpu/lts_assembly_mpi_cuda.cu
+++ b/src/gpu/lts_assembly_mpi_cuda.cu
@@ -28,7 +28,7 @@
  */
 
 #include "mesh_constants_gpu.h"
-
+#include <string.h>
 
 /* ----------------------------------------------------------------------------------------------- */
 
diff --git a/src/gpu/prepare_mesh_constants_cuda.cu b/src/gpu/prepare_mesh_constants_cuda.cu
index a7be54cc0..2f91a4dc2 100644
--- a/src/gpu/prepare_mesh_constants_cuda.cu
+++ b/src/gpu/prepare_mesh_constants_cuda.cu
@@ -29,6 +29,7 @@
 
 #include "mesh_constants_gpu.h"
 #include "prepare_constants_cuda.h"
+#include <string.h>
 
 #ifdef USE_CUDA
 #ifdef USE_OLDER_CUDA4_GPU