diff --git a/build/build.tcl b/build/build.tcl
index 3a968853..e6807806 100644
--- a/build/build.tcl
+++ b/build/build.tcl
@@ -67,7 +67,7 @@ proc ip_address {string} {
 }
 
 set timeout 100
-expect_before timeout abort
+expect_after timeout abort
 
 set ip [ip_address [lindex $argv 0]]
 set gw [ip_address [lindex $argv 1]]
diff --git a/build/sims/build.tcl b/build/sims/build.tcl
index ce4101a6..764488cf 100644
--- a/build/sims/build.tcl
+++ b/build/sims/build.tcl
@@ -14,12 +14,21 @@ proc start_dskdmp {} {
 proc mount_tape {file} {
     respond "sim>" "at mta0 $file\r"
     respond "sim>" "c\r"
+    expect -timeout 2 "BUGPC/" {
+        type "\033P"
+    } timeout {
+	;
+    }
 }
 
 proc create_tape {file} {
     respond "sim>" "at mta0 $file\r"
     respond "sim>" "c\r"
-    respond "BUGPC/" "\033P"
+    expect -timeout 2 "BUGPC/" {
+        type "\033P"
+    } timeout {
+	;
+    }
 }
 
 proc quit_emulator {} {