diff --git a/homeassistant/package_constraints.txt b/homeassistant/package_constraints.txt
index e24ccc4fac9..b1d82e3c58b 100644
--- a/homeassistant/package_constraints.txt
+++ b/homeassistant/package_constraints.txt
@@ -39,7 +39,7 @@ ifaddr==0.2.0
 Jinja2==3.1.4
 lru-dict==1.3.0
 mutagen==1.47.0
-orjson==3.10.3
+orjson==3.9.15
 packaging>=23.1
 paho-mqtt==1.6.1
 Pillow==10.3.0
diff --git a/pyproject.toml b/pyproject.toml
index bfae6c15cd6..c3e03374b55 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -53,7 +53,7 @@ dependencies    = [
     "cryptography==42.0.5",
     "Pillow==10.3.0",
     "pyOpenSSL==24.1.0",
-    "orjson==3.10.3",
+    "orjson==3.9.15",
     "packaging>=23.1",
     "pip>=21.3.1",
     "psutil-home-assistant==0.0.1",
diff --git a/requirements.txt b/requirements.txt
index 2701c7b6099..05b0eb35c1e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -28,7 +28,7 @@ PyJWT==2.8.0
 cryptography==42.0.5
 Pillow==10.3.0
 pyOpenSSL==24.1.0
-orjson==3.10.3
+orjson==3.9.15
 packaging>=23.1
 pip>=21.3.1
 psutil-home-assistant==0.0.1