diff --git a/jenkins/pre-build.sh b/jenkins/pre-build.sh
new file mode 100755
index 000000000..0c7173e2d
--- /dev/null
+++ b/jenkins/pre-build.sh
@@ -0,0 +1,12 @@
+#! /bin/bash
+
+./bin/genEvalSpecializations.py
+
+if test -n "$(git diff)"; then
+    echo "The generated source files have been manually edited or the "
+    echo "code generator has been modified but not been run before "
+    echo "proposing the branch for merging."
+    exit 1
+else
+    exit 0
+fi