diff --git a/dat/sokoban.des b/dat/sokoban.des
index 56f04e3a4..b772f96ee 100644
--- a/dat/sokoban.des
+++ b/dat/sokoban.des
@@ -508,6 +508,9 @@ TRAP:"hole",(21,01)
 TRAP:"hole",(22,01)
 TRAP:"hole",(23,01)
 
+MONSTER:'m',"giant mimic", random, m_object "boulder"
+MONSTER:'m',"giant mimic", random, m_object "boulder"
+
 # Random objects
 OBJECT:'%',random,random
 OBJECT:'%',random,random
@@ -599,6 +602,8 @@ TRAP:"hole",(20,01)
 TRAP:"hole",(21,01)
 TRAP:"hole",(22,01)
 
+MONSTER:'m',"giant mimic", random, m_object "boulder"
+MONSTER:'m',"giant mimic", random, m_object "boulder"
 
 # Random objects
 OBJECT:'%',random,random