diff --git a/jetty-websocket.spec b/jetty-websocket.spec
index 1a4e80d..c2f610d 100644
--- a/jetty-websocket.spec
+++ b/jetty-websocket.spec
@@ -47,6 +47,9 @@ BuildRequires:  mvn(org.eclipse.jetty:jetty-server) >= %{version}
 BuildRequires:  mvn(org.eclipse.jetty:jetty-servlet) >= %{version}
 BuildRequires:  mvn(org.eclipse.jetty:jetty-util) >= %{version}
 BuildRequires:  mvn(org.eclipse.jetty:jetty-xml) >= %{version}
+BuildConflicts: java >= 12
+BuildConflicts: java-devel >= 12
+BuildConflicts: java-headless >= 12
 Requires:       jboss-websocket-1.0-api
 BuildArch:      noarch
 # jp_minimal doesn't have main package