CI: use bash explicitly for assert tests
diff --git a/Makefile b/Makefile
index 7ec8d91..9b9f669 100644
--- a/Makefile
+++ b/Makefile
@@ -58,7 +58,7 @@
 	tail -n 1 xslt/idsCorpus-template.xml  >> $@
 
 test: models/dereko_domains_s.classifier i5valid
-	- sh test/test-xml.sh
+	- bash test/test-xml.sh
 
 i5: $(foreach year,$(YEARS),$(TARGET_DIR)/dnb$(year).i5.xml)