diff --git a/src/mem/arena/mem_arena.c b/src/mem/arena/mem_arena.c
index ea1934c..ea6cfe1 100644
--- a/src/mem/arena/mem_arena.c
+++ b/src/mem/arena/mem_arena.c
@@ -80,13 +80,14 @@ void *wapp_mem_arena_alloc_aligned(Arena *arena, u64 size, u64 alignment) {
 
 #ifdef WAPP_PLATFORM_WINDOWS
   if (!(arena->committed)) {
-    output = (u8 *)wapp_mem_util_alloc(output, size, WAPP_MEM_ACCESS_READ_WRITE,
-                                       WAPP_MEM_ALLOC_COMMIT,
-                                       WAPP_MEM_INIT_UNINITIALISED);
+    output = (u8 *)wapp_mem_util_alloc(
+        alloc_start, (uptr)(arena->offset) - (uptr)(alloc_start),
+        WAPP_MEM_ACCESS_READ_WRITE, WAPP_MEM_ALLOC_COMMIT,
+        WAPP_MEM_INIT_INITIALISED);
   }
-#endif // ifdef WAPP_PLATFORM_WINDOWS
-
+#else
   memset(output, 0, size);
+#endif // ifdef WAPP_PLATFORM_WINDOWS
 
   return (void *)output;
 }
diff --git a/src/strings/dstr/dstr.c b/src/strings/dstr/dstr.c
index 2e2ea78..a583db9 100644
--- a/src/strings/dstr/dstr.c
+++ b/src/strings/dstr/dstr.c
@@ -115,7 +115,7 @@ StringUpdate wapp_dstr_concat(String **dst, const char *src, Arena *arena) {
 #else
   char str[new_length + 1];
   memset(str, 0, new_length + 1);
-#endif
+#endif /* ifdef WAPP_PLATFORM_WINDOWS */
 
   strncpy(str, (*dst)->buf, (*dst)->size);
   strncat(str, src, new_length + 1 - (*dst)->size);