diff --git a/rocket/src/main/scala/icache.scala b/rocket/src/main/scala/icache.scala
index d0437716..318b2896 100644
--- a/rocket/src/main/scala/icache.scala
+++ b/rocket/src/main/scala/icache.scala
@@ -172,7 +172,7 @@ class ICache(implicit c: ICacheConfig, lnconf: LogicalNetworkConfiguration) exte
   val s2_miss = s2_valid && !s2_any_tag_hit
   rdy := state === s_ready && !s2_miss
 
-  Assert(!c.co.isVoluntary(io.mem.grant.bits.payload) || !io.mem.grant.valid, "UncachedRequestors shouldn't get voluntary grants.")
+  assert(!c.co.isVoluntary(io.mem.grant.bits.payload) || !io.mem.grant.valid, "UncachedRequestors shouldn't get voluntary grants.")
   val (rf_cnt, refill_done) = Counter(io.mem.grant.valid, REFILL_CYCLES)
   val repl_way = if (c.dm) UFix(0) else LFSR16(s2_miss)(log2Up(c.assoc)-1,0)