diff --git a/misc/t_boulder.arc b/misc/t_boulder.arc
index cedb1934e..82b51737a 100644
--- a/misc/t_boulder.arc
+++ b/misc/t_boulder.arc
@@ -9,4 +9,5 @@ material 64
 editable 1024
 name_pl boulders
 client_type 8012
+is_thrown 1
 end
diff --git a/misc/t_lboulder.arc b/misc/t_lboulder.arc
index 507fb8e88..a41b7e323 100644
--- a/misc/t_lboulder.arc
+++ b/misc/t_lboulder.arc
@@ -9,4 +9,5 @@ material 64
 editable 1024
 name_pl large boulders
 client_type 8012
+is_thrown 1
 end
diff --git a/misc/t_lrock.arc b/misc/t_lrock.arc
index d98056f07..19b954d37 100644
--- a/misc/t_lrock.arc
+++ b/misc/t_lrock.arc
@@ -9,4 +9,5 @@ editable 1024
 material 64
 name_pl large rocks
 client_type 8012
+is_thrown 1
 end
diff --git a/misc/t_rock.arc b/misc/t_rock.arc
index 60e5a0988..dc94df914 100644
--- a/misc/t_rock.arc
+++ b/misc/t_rock.arc
@@ -10,4 +10,5 @@ material 64
 magicmap black
 name_pl rocks
 client_type 8012
+is_thrown 1
 end