diff --git a/.travis.yml b/.travis.yml
index 840b414801..0045c5e0b1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -75,6 +75,10 @@ matrix:
           compiler: clang
           dist: trusty
           env: T=debug C="--with-mbedtls --without-ssl"
+        - os: linux
+          compiler: clang
+          dist: trusty
+          env: T=debug C="--disable-threaded-resolver"
         - os: linux
           compiler: clang
           dist: trusty