diff --git a/code/modules/reagents/chemistry/reagents/water.dm b/code/modules/reagents/chemistry/reagents/water.dm
index 83956eb56c9..e2875a301fe 100644
--- a/code/modules/reagents/chemistry/reagents/water.dm
+++ b/code/modules/reagents/chemistry/reagents/water.dm
@@ -77,7 +77,7 @@
 	data = list("donor" = null,
 				"viruses" = null,
 				"blood_DNA" = null,
-				"blood_type" = null,
+				"blood_type" = "O-",
 				"blood_colour" = "#A10808",
 				"resistances" = null,
 				"trace_chem" = null,