diff --git a/scripts/build_monado.sh b/scripts/build_monado.sh
index c6aefdb..ff9e88f 100755
--- a/scripts/build_monado.sh
+++ b/scripts/build_monado.sh
@@ -29,6 +29,7 @@ mkdir -p build
 cd build
 export PKG_CONFIG_PATH="${PREFIX}/lib/pkgconfig"
 cmake -DCMAKE_BUILD_TYPE=Release \
+    -DXRT_HAVE_SYSTEM_CJSON=NO \
     -DCMAKE_LIBDIR="${PREFIX}/lib" \
     -DCMAKE_INSTALL_PREFIX="${PREFIX}" \
     -DCMAKE_C_FLAGS="-Wl,-rpath ${PREFIX}/lib" \
diff --git a/scripts/build_wivrn.sh b/scripts/build_wivrn.sh
index 2b3fc66..8b8ef52 100755
--- a/scripts/build_wivrn.sh
+++ b/scripts/build_wivrn.sh
@@ -28,6 +28,7 @@ rm -rf build
 mkdir -p build
 cd build
 cmake -B build-server -DCMAKE_BUILD_TYPE=Release \
+    -DXRT_HAVE_SYSTEM_CJSON=NO \
     -DWIVRN_BUILD_CLIENT=OFF \
     -DCMAKE_INSTALL_PREFIX="${PREFIX}" \
     .. -GNinja