diff --git a/dev-libs/cJSON/cJSON-1.7.18.ebuild b/dev-libs/cJSON/cJSON-1.7.18.ebuild
index 44295cfe95b28..43df8dc36ae08 100644
--- a/dev-libs/cJSON/cJSON-1.7.18.ebuild
+++ b/dev-libs/cJSON/cJSON-1.7.18.ebuild
@@ -15,6 +15,10 @@ KEYWORDS="~alpha amd64 arm arm64 hppa ~loong ~mips ppc ppc64 ~riscv sparc x86"
 IUSE="test"
 RESTRICT="!test? ( test )"
 
+PATCHES=(
+	"${FILESDIR}"/${PV}-cmake4.patch
+)
+
 src_prepare() {
 	cmake_src_prepare
 
diff --git a/dev-libs/cJSON/files/1.7.18-cmake4.patch b/dev-libs/cJSON/files/1.7.18-cmake4.patch
new file mode 100644
index 0000000000000..b7658bdf1422f
--- /dev/null
+++ b/dev-libs/cJSON/files/1.7.18-cmake4.patch
@@ -0,0 +1,13 @@
+
+Set cmake_minimum_required(VERSION) to 3.10 so that it works with cmake-4.
+Bug: https://bugs.gentoo.org/954223
+
+--- cJSON-1.7.18/CMakeLists.txt~	2025-04-22 21:00:57.000000000 +0200
++++ cJSON-1.7.18/CMakeLists.txt	2025-04-22 21:01:15.694382211 +0200
+@@ -1,5 +1,5 @@
+ set(CMAKE_LEGACY_CYGWIN_WIN32 0)
+-cmake_minimum_required(VERSION 3.0)
++cmake_minimum_required(VERSION 3.10)
+ 
+ project(cJSON
+     VERSION 1.7.18