diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 3e52e6e..9d7e74d 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -1717,6 +1717,36 @@
     fi
 }
 
+support_test_cmake_out_of_source () {
+    distrib_id=""
+    distrib_ver=""
+    distrib_ver_minor=""
+    distrib_ver_major=""
+
+    # Attempt to parse lsb-release to find out distribution and version. If not
+    # found this should fail safe (test is supported).
+    if [[ -f /etc/lsb-release ]]; then
+
+        while read -r lsb_line; do
+            case "$lsb_line" in
+                "DISTRIB_ID"*) distrib_id=${lsb_line/#DISTRIB_ID=};;
+                "DISTRIB_RELEASE"*) distrib_ver=${lsb_line/#DISTRIB_RELEASE=};;
+            esac
+        done < /etc/lsb-release
+
+        distrib_ver_major="${distrib_ver%%.*}"
+        distrib_ver="${distrib_ver#*.}"
+        distrib_ver_minor="${distrib_ver%%.*}"
+    fi
+
+    # Running the out of source CMake test on Ubuntu 16.04 using more than one
+    # processor (as the CI does) can create a race condition whereby the build
+    # fails to see a generated file, despite that file actually having been
+    # generated. This problem appears to go away with 18.04 or newer, so make
+    # the out of source tests unsupported on Ubuntu 16.04.
+    [ "$distrib_id" != "Ubuntu" ] || [ "$distrib_ver_major" -gt 16 ]
+}
+
 component_test_cmake_out_of_source () {
     msg "build: cmake 'out-of-source' build"
     MBEDTLS_ROOT_DIR="$PWD"