diff --git a/appveyor.sh b/appveyor.sh
index a2925e647a..5f39dddd27 100644
--- a/appveyor.sh
+++ b/appveyor.sh
@@ -137,6 +137,7 @@ if [[ "${TFLAGS}" != 'skipall' ]] && \
   elif [ -x "$(cygpath 'C:/msys64/usr/bin/curl.exe')" ]; then
     TFLAGS+=" -ac $(cygpath 'C:/msys64/usr/bin/curl.exe')"
   fi
+  TFLAGS+=' -j0'
   if [ "${BUILD_SYSTEM}" = 'CMake' ]; then
     cmake --build _bld --config "${PRJ_CFG}" --target test-ci
   else
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 499d01150f..8c40135ecb 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -88,6 +88,6 @@ add_runtests(test-am        "-a -am")
 add_runtests(test-full      "-a -p -r")
 # ~flaky means that it'll ignore results of tests using the flaky keyword
 add_runtests(test-nonflaky  "-a -p ~flaky ~timing-dependent")
-add_runtests(test-ci        "-a -p ~flaky ~timing-dependent -r -rm")
+add_runtests(test-ci        "-a -p ~flaky ~timing-dependent -r -rm -j2")
 add_runtests(test-torture   "-a -t")
 add_runtests(test-event     "-a -e")
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 4b58fad24b..54b9af66a8 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -133,7 +133,7 @@ TEST_E = -a -e
 TEST_NF = -a -p ~flaky ~timing-dependent
 
 # special CI target derived from nonflaky with CI-specific flags
-TEST_CI = $(TEST_NF) -r -rm
+TEST_CI = $(TEST_NF) -r -rm -j2
 endif
 
 CD2NROFF = $(top_srcdir)/scripts/cd2nroff $< >$@