diff --git a/mpbb b/mpbb
index 7dfeabc..1432eef 100755
--- a/mpbb
+++ b/mpbb
@@ -60,7 +60,7 @@ parseopt prefix:,work-dir: "$@" || exit
 option_failcache_dir=${option_work_dir}/failcache
 option_license_db_dir=${option_work_dir}/license_db
 option_mirrordb_url=""
-option_mirrordb_credentials=""
+option_mirrordb_credentials_file=""
 
 # Inform the user if old repositories are still present.
 if [[ -d ${option_work_dir}/tools/.svn ]]; then
diff --git a/mpbb-install-port b/mpbb-install-port
index bcf5f8e..b5c5d06 100644
--- a/mpbb-install-port
+++ b/mpbb-install-port
@@ -75,7 +75,7 @@ install-port() {
         if [ -n "$option_mirrordb_url" ]; then
             echo "Waiting for '$port' to be mirrored."
             if "${option_prefix}/bin/port-tclsh" "${thisdir}/tools/wait-for-mirror.tcl" \
-                    "$option_mirrordb_url" "$option_mirrordb_credentials" "$port"; then
+                    "$option_mirrordb_url" "$option_mirrordb_credentials_file" "$port"; then
                 echo "Mirroring of '$port' done. Retrying fetch."
                 if ! "${option_prefix}/bin/port" -d fetch "$@"; then
                     echo "Second fetch of '$port' failed."
diff --git a/tools/wait-for-mirror.tcl b/tools/wait-for-mirror.tcl
index 148d491..8edc247 100755
--- a/tools/wait-for-mirror.tcl
+++ b/tools/wait-for-mirror.tcl
@@ -5,10 +5,18 @@
 # periodically until it has been, or timeout is reached.
 
 if {$argc != 3} {
-    error "Usage: wait-for-mirror.tcl mirrorcache_baseurl mirrorcache_credentials portname"
+    error "Usage: wait-for-mirror.tcl mirrorcache_baseurl mirrorcache_credentials_file portname"
 }
 
-lassign $argv mirrorcache_baseurl mirrorcache_credentials portname
+lassign $argv mirrorcache_baseurl mirrorcache_credentials_file portname
+try {
+    set fd [open $mirrorcache_credentials_file r]
+    set mirrorcache_credentials [gets $fd]
+    close $fd
+} on error {eMessage} {
+    puts stderr "Failed to load credentials file '$mirrorcache_credentials_file': $eMessage"
+    exit 1
+}
 
 package require macports
 source [file join [file dirname [info script]] mirrordb.tcl]