diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index afc3c9d97..11e2b2f41 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -1149,10 +1149,10 @@ component_test_allow_sha1 () {
 
 component_build_mingw () {
     msg "build: Windows cross build - mingw64, make (Link Library)" # ~ 30s
-    make CC=i686-w64-mingw32-gcc AR=i686-w64-mingw32-ar LD=i686-w64-minggw32-ld CFLAGS='-Werror -Wall -Wextra' WINDOWS_BUILD=1 lib programs
+    make CC=i686-w64-mingw32-gcc AR=i686-w64-mingw32-ar LD=i686-w64-minggw32-ld CFLAGS='-Werror -Wall -Wextra' WINDOWS_BUILD=1 lib programs -j1
 
     # note Make tests only builds the tests, but doesn't run them
-    make CC=i686-w64-mingw32-gcc AR=i686-w64-mingw32-ar LD=i686-w64-minggw32-ld CFLAGS='-Werror' WINDOWS_BUILD=1 tests
+    make CC=i686-w64-mingw32-gcc AR=i686-w64-mingw32-ar LD=i686-w64-minggw32-ld CFLAGS='-Werror' WINDOWS_BUILD=1 tests -j1
     make WINDOWS_BUILD=1 clean
 
     msg "build: Windows cross build - mingw64, make (DLL)" # ~ 30s