diff --git a/src/http/zlib.zig b/src/http/zlib.zig
index 473bf236fe..b038db3e17 100644
--- a/src/http/zlib.zig
+++ b/src/http/zlib.zig
@@ -9,7 +9,7 @@ pub fn get(allocator: std.mem.Allocator) *MutableString {
 
 pub fn put(mutable: *MutableString) void {
     mutable.reset();
-    var node: BufferPool.Node = @fieldParentPtr("data", mutable);
+    const node: *BufferPool.Node = @fieldParentPtr("data", mutable);
     node.release();
 }
 
diff --git a/src/paths/path_buffer_pool.zig b/src/paths/path_buffer_pool.zig
index 4c950f8095..dd1cd77b65 100644
--- a/src/paths/path_buffer_pool.zig
+++ b/src/paths/path_buffer_pool.zig
@@ -13,7 +13,13 @@ fn PathBufferPoolT(comptime T: type) type {
 
         pub fn put(buffer: *const T) void {
             // there's no deinit function on T so @constCast is fine
-            var node: *Pool.Node = @alignCast(@fieldParentPtr("data", @constCast(buffer)));
+            const node: *Pool.Node = @alignCast(@fieldParentPtr("data", @constCast(buffer)));
+            // Validate the allocator pointer to catch use-after-free or invalid buffer pointers.
+            // A valid allocator should have non-null ptr and vtable fields.
+            if (comptime Environment.isDebug) {
+                bun.debugAssert(@intFromPtr(node.allocator.ptr) != 0);
+                bun.debugAssert(@intFromPtr(node.allocator.vtable) != 0);
+            }
             node.release();
         }