diff --git a/dev-libs/libmongocrypt/libmongocrypt-1.15.2.ebuild b/dev-libs/libmongocrypt/libmongocrypt-1.15.2.ebuild
index 081fe43..eed5895 100644
--- a/dev-libs/libmongocrypt/libmongocrypt-1.15.2.ebuild
+++ b/dev-libs/libmongocrypt/libmongocrypt-1.15.2.ebuild
@@ -35,6 +35,7 @@ src_configure() {
 	local mycmakeargs=(
 		-DCMAKE_SKIP_RPATH=ON
 		-DUSE_SHARED_LIBBSON=ON
+		-DMONGOCRYPT_MONGOC_DIR=USE-SYSTEM
 		-DENABLE_ONLINE_TESTS="$(usex test ON OFF)"
 		-DBUILD_VERSION=${PV}
 		-DENABLE_STATIC="$(usex static-libs ON OFF)"