diff --git a/quark/cuda_quark_blake512.cu b/quark/cuda_quark_blake512.cu
index c7f0df6..5ac6cdb 100644
--- a/quark/cuda_quark_blake512.cu
+++ b/quark/cuda_quark_blake512.cu
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <memory.h>
+#include <sys/types.h> // off_t
 
 #include "cuda_helper.h"
 
diff --git a/quark/cuda_quark_groestl512.cu b/quark/cuda_quark_groestl512.cu
index 1580b27..2a946b9 100644
--- a/quark/cuda_quark_groestl512.cu
+++ b/quark/cuda_quark_groestl512.cu
@@ -2,6 +2,7 @@
 
 #include <stdio.h>
 #include <memory.h>
+#include <sys/types.h> // off_t
 
 #include "cuda_helper.h"
 
diff --git a/quark/cuda_quark_keccak512.cu b/quark/cuda_quark_keccak512.cu
index de89505..b438ab0 100644
--- a/quark/cuda_quark_keccak512.cu
+++ b/quark/cuda_quark_keccak512.cu
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <memory.h>
+#include <sys/types.h> // off_t
 
 #include "cuda_helper.h"