diff --git a/tests/runtests.pl b/tests/runtests.pl
index 81baf2cbe0..57e3152392 100755
--- a/tests/runtests.pl
+++ b/tests/runtests.pl
@@ -2514,9 +2514,9 @@ EOHELP
     shift @ARGV;
 }
 
-# Detect a test bundle build
+# Detect a test bundle build.
+# Do not look for 'units' because not all configurations build it.
 if(-e $LIBDIR . "libtests" . exe_ext('TOOL') &&
-   -e $UNITDIR . "units" . exe_ext('TOOL') &&
    -e $SRVDIR . "servers" . exe_ext('SRV')) {
     # use test bundles
     $bundle=1;