diff --git a/.travis/script.sh b/.travis/script.sh
index 2dd4bee50..77737e4e8 100755
--- a/.travis/script.sh
+++ b/.travis/script.sh
@@ -368,7 +368,7 @@ set -x
 
 [ $BUILD_TARGET != posix-ncp ] || {
     ./bootstrap || die
-    COVERAGE=1 NODE_TYPE=ncp-sim make -f examples/Makefile-posix check || die
+    NODE_TYPE=ncp-sim make -f examples/Makefile-posix check || die
 }
 
 [ $BUILD_TARGET != toranj-test-framework ] || {
diff --git a/tests/toranj/start.sh b/tests/toranj/start.sh
index 0594411ee..9dc622234 100755
--- a/tests/toranj/start.sh
+++ b/tests/toranj/start.sh
@@ -83,6 +83,7 @@ cd ../..
 ./bootstrap || die
 ./configure                             \
     CPPFLAGS='-DOPENTHREAD_PROJECT_CORE_CONFIG_FILE=\"../tests/toranj/openthread-core-toranj-config.h\"' \
+    --enable-coverage                   \
     --enable-ncp-app=all                \
     --with-ncp-bus=uart                 \
     --with-examples=posix               \