2 files changed, 2 insertions, 2 deletions
diff --git a/src/vector.c b/src/vector.c
index b372647..5d33cbd 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -169,7 +169,7 @@ vector_append (vector_t vector, void *data, size_t len)
 }
 
 int
-vector_prepend (vector_t vector, void *data, ssize_t len)
+vector_prepend (vector_t vector, void *data, size_t len)
 {
   return vector_insert (vector, data, len, INSERT_PREPEND);
 }
diff --git a/src/vector.h b/src/vector.h
index 1dbf638..0a096f0 100644
--- a/src/vector.h
+++ b/src/vector.h
@@ -50,7 +50,7 @@ extern "C"
  *          0 upon successful insert.
  */
   extern int vector_append (vector_t vector, void *data, size_t len);
-  extern int vector_prepend (vector_t vector, void *data, ssize_t len);
+  extern int vector_prepend (vector_t vector, void *data, size_t len);
 
 /*
  * A pointer to the data at position "pos" (zero based) is returned and the