diff --git a/raid/memory.c b/raid/memory.c
index d6230966..429e724a 100644
--- a/raid/memory.c
+++ b/raid/memory.c
@@ -119,7 +119,7 @@ static const unsigned STRIDE_NOISE[16] = {
 	1, 4, 0, 7, 3, 6, 2, 5
 };
 
-void **raid_malloc_vector_align(int n, size_t size, size_t align_size, ssize_t displacement_size, ssize_t wrap_size, void **freeptr)
+void **raid_malloc_vector_align(int n, size_t size, size_t align_size, size_t displacement_size, size_t wrap_size, void **freeptr)
 {
 	void **v;
 	unsigned char *va;
diff --git a/raid/memory.h b/raid/memory.h
index 3cc6d768..def9728a 100644
--- a/raid/memory.h
+++ b/raid/memory.h
@@ -108,7 +108,7 @@ void **raid_malloc_vector(int n, size_t size, void **freeptr);
  * Freeing requires two calls: free(*freeptr) for the data buffer,
  * and free(v) for the pointer vector.
  */
-void **raid_malloc_vector_align(int n, size_t size, size_t align_size, ssize_t displacement_size, ssize_t wrap_size, void **freeptr);
+void **raid_malloc_vector_align(int n, size_t size, size_t align_size, size_t displacement_size, size_t wrap_size, void **freeptr);
 
 /**
  * Fills the memory vector with pseudo-random data based on the specified seed.