diff --git a/.changeset/forms-initdeflate-fix.md b/.changeset/forms-initdeflate-fix.md
new file mode 100644
index 000000000..5bf4e141e
--- /dev/null
+++ b/.changeset/forms-initdeflate-fix.md
@@ -0,0 +1,5 @@
+---
+'@react-pdf/render': patch
+---
+
+Fix `appearance.initDeflate is not a function` when rendering checkboxes with upstream pdfkit
diff --git a/packages/render/src/utils/parseFormOptions.ts b/packages/render/src/utils/parseFormOptions.ts
index 991aeb28a..6887a1479 100644
--- a/packages/render/src/utils/parseFormOptions.ts
+++ b/packages/render/src/utils/parseFormOptions.ts
@@ -75,8 +75,6 @@ const getAppearance = (
     },
   });
 
-  appearance.initDeflate();
-
   appearance.write(
     `/Tx BMC\nq\n/ZaDi ${height * 0.8} Tf\nBT\n${width * 0.45} ${
       height / 4
diff --git a/packages/render/tests/primitives/renderForm.test.ts b/packages/render/tests/primitives/renderForm.test.ts
index d3dcd89c2..188d72536 100644
--- a/packages/render/tests/primitives/renderForm.test.ts
+++ b/packages/render/tests/primitives/renderForm.test.ts
@@ -82,7 +82,6 @@ describe('primitive renderCheckbox', () => {
     const ctx = createCTX();
     ctx._acroform = { fonts: {} };
     ctx.ref = vi.fn(() => ({
-      initDeflate: vi.fn(),
       write: vi.fn(),
       end: vi.fn(),
     }));