diff --git a/internal/sandbox/config.go b/internal/sandbox/config.go
index e7a1d44..f270f2d 100644
--- a/internal/sandbox/config.go
+++ b/internal/sandbox/config.go
@@ -86,7 +86,7 @@ func DefaultConfig() *Config {
 			},
 			RWX: []string{
 				"{HOME}/.config/ollie",
-				"{OLLIE_9MOUNT}",
+				"{OLLIE}",
 				"{HOME}/mnt/ollie",
 			},
 		},
@@ -103,7 +103,7 @@ func DefaultConfig() *Config {
 			"LANG",
 			"TERM",
 			"OLLIE_SESSION_ID",
-			"OLLIE_9MOUNT",
+			"OLLIE",
 			"OLLIE_MEMORY_PATH",
 		},
 		Advanced: AdvancedConfig{
@@ -350,7 +350,7 @@ func SystemDefaults() LayeredConfig {
 			"LANG",
 			"TERM",
 			"OLLIE_SESSION_ID",
-			"OLLIE_9MOUNT",
+			"OLLIE",
 		},
 	}
 }
diff --git a/pkg/agent/core.go b/pkg/agent/core.go
index 2be132c..a0d3d8f 100644
--- a/pkg/agent/core.go
+++ b/pkg/agent/core.go
@@ -359,6 +359,13 @@ func (s *agentCore) SetSessionID(newID string) error {
 		if srv, ok := s.dispatcher.GetServer("execute"); ok {
 			if es, ok := srv.(tools.EnvSetter); ok {
 				es.SetEnv("OLLIE_SESSION_ID", newID)
+				// Ensure OLLIE is always set, resolving the default if unset.
+				ollie := os.Getenv("OLLIE")
+				if ollie == "" {
+					home, _ := os.UserHomeDir()
+					ollie = home + "/mnt/ollie"
+				}
+				es.SetEnv("OLLIE", ollie)
 			}
 		}
 	}
@@ -959,7 +966,7 @@ func (s *agentCore) handleCommand(ctx context.Context, input string, handler Eve
 		if cmd == "/tools" {
 			subdir = "t"
 		}
-		mount := os.Getenv("OLLIE_9MOUNT")
+		mount := os.Getenv("OLLIE")
 		if mount == "" {
 			home, _ := os.UserHomeDir()
 			mount = home + "/mnt/ollie"