diff --git a/shm/shm.c b/shm/shm.c
index 194118c..eb285b7 100644
--- a/shm/shm.c
+++ b/shm/shm.c
@@ -1,6 +1,6 @@
 #include "shm.h"
 
-int sysv_shm_open(int size, int flags, int perm) {
+int sysv_shm_open(size_t size, int flags, int perm) {
     int shm_id;
 
     if(size) {
diff --git a/shm/shm.go b/shm/shm.go
index c85784b..89f8e4c 100644
--- a/shm/shm.go
+++ b/shm/shm.go
@@ -67,7 +67,7 @@ func Open(id int) (*Segment, error) {
 // creation flags supported by the shmget() call, as well as specifying permissions.
 //
 func OpenSegment(size int, flags SharedMemoryFlags, perms os.FileMode) (*Segment, error) {
-	if shmid, err := C.sysv_shm_open(C.int(size), C.int(flags), C.int(perms)); err == nil {
+	if shmid, err := C.sysv_shm_open(C.size_t(size), C.int(flags), C.int(perms)); err == nil {
 		if actual_size, err := C.sysv_shm_get_size(shmid); err != nil {
 			return nil, fmt.Errorf("Failed to retrieve SHM size: %v", err)
 		} else {
diff --git a/shm/shm.h b/shm/shm.h
index 6f8f1bb..18b9536 100644
--- a/shm/shm.h
+++ b/shm/shm.h
@@ -8,7 +8,7 @@
 
 #define IPC_KEY_PROJID 0x42
 
-int sysv_shm_open(int size, int flags, int perm);
+int sysv_shm_open(size_t size, int flags, int perm);
 void *sysv_shm_attach(int shm_id);
 int sysv_shm_detach(void *addr);
 int sysv_shm_write(int shm_id, void* input, int len, int offset);