diff --git a/src/resizable.c b/src/resizable.c
index fd86133..895f80a 100644
--- a/src/resizable.c
+++ b/src/resizable.c
@@ -42,12 +42,12 @@ apfl_resizable_grow_cap(size_t elem_size, void **mem, size_t *len, size_t *cap,
         return true;
     }
 
-    size_t newcap = *cap + elem_size * inc_cap;
+    size_t newcap = *cap + inc_cap;
 
     // TODO: We currently simply grow the memory to have space for exactly
     //       inc_cap more elements. It would probably be smarter to grow the
     //       memory a bit larger to reduce calls to realloc.
-    void *newmem = realloc(*mem, newcap);
+    void *newmem = realloc(*mem, newcap * elem_size);
     if (newmem == NULL) {
         return false;
     }