diff --git a/Quake/pr_cmds.c b/Quake/pr_cmds.c
index ac8344ca..ff886623 100644
--- a/Quake/pr_cmds.c
+++ b/Quake/pr_cmds.c
@@ -1222,6 +1222,10 @@ static void PF_lightstyle (void)
 	style = G_FLOAT(OFS_PARM0);
 	val = G_STRING(OFS_PARM1);
 
+// bounds check to avoid clobbering sv struct
+	if (style < 0 || style >= MAX_LIGHTSTYLES)
+		Host_Error("PF_lightstyle: style = %d", style);
+
 // change the string in sv
 	sv.lightstyles[style] = val;