diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 8bb6d14..afc3c9d 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -982,7 +982,7 @@
 
 component_test_make_shared () {
     msg "build/test: make shared" # ~ 40s
-    make SHARED=1 all check
+    make SHARED=1 all check -j1
 }
 
 component_test_m32_o0 () {
@@ -1156,8 +1156,8 @@
     make WINDOWS_BUILD=1 clean
 
     msg "build: Windows cross build - mingw64, make (DLL)" # ~ 30s
-    make CC=i686-w64-mingw32-gcc AR=i686-w64-mingw32-ar LD=i686-w64-minggw32-ld CFLAGS='-Werror -Wall -Wextra' WINDOWS_BUILD=1 SHARED=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 SHARED=1 tests
+    make CC=i686-w64-mingw32-gcc AR=i686-w64-mingw32-ar LD=i686-w64-minggw32-ld CFLAGS='-Werror -Wall -Wextra' WINDOWS_BUILD=1 SHARED=1 lib programs -j1
+    make CC=i686-w64-mingw32-gcc AR=i686-w64-mingw32-ar LD=i686-w64-minggw32-ld CFLAGS='-Werror -Wall -Wextra' WINDOWS_BUILD=1 SHARED=1 tests -j1
     make WINDOWS_BUILD=1 clean
 }
 support_build_mingw() {