diff --git a/libgomp/configure b/libgomp/configure
index 9a9d30c851d..ad245b47dff 100755
--- a/libgomp/configure
+++ b/libgomp/configure
@@ -16638,6 +16638,13 @@ done
 
 # Fallback if 'perl' is available.
 if test -z "$FLOCK"; then
+  # These need to be absolute paths, yet at the same time need to
+  # canonicalize only relative paths, because then amd will not unmount
+  # drives. Thus the use of PWDCMD: set it to 'pawd' or 'amq -w' if using amd.
+  case $srcdir in
+    [\\/$]* | ?:[\\/]*) libgomp_abs_srcdir=${srcdir} ;;
+    *) libgomp_abs_srcdir=`cd "$srcdir" && ${PWDCMD-pwd} || echo "$srcdir"` ;;
+  esac
   # Extract the first word of "perl", so it can be a program name with args.
 set dummy perl; ac_word=$2
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
@@ -16655,7 +16662,7 @@ do
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
   if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_prog_FLOCK="\$(abs_top_srcdir)/testsuite/flock"
+    ac_cv_prog_FLOCK="$libgomp_abs_srcdir/testsuite/flock"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
   fi
diff --git a/libgomp/configure.ac b/libgomp/configure.ac
index 63129be7e3d..1730c62c74c 100644
--- a/libgomp/configure.ac
+++ b/libgomp/configure.ac
@@ -343,7 +343,16 @@ AC_MSG_NOTICE([checking for flock implementation])
 AC_CHECK_PROGS(FLOCK, flock)
 # Fallback if 'perl' is available.
 if test -z "$FLOCK"; then
-  AC_CHECK_PROG(FLOCK, perl, \$(abs_top_srcdir)/testsuite/flock)
+  # These need to be absolute paths, yet at the same time need to
+  # canonicalize only relative paths, because then amd will not unmount
+  # drives. Thus the use of PWDCMD: set it to 'pawd' or 'amq -w' if using amd.
+  case $srcdir in
+changequote(,)dnl
+    [\\/$]* | ?:[\\/]*) libgomp_abs_srcdir=${srcdir} ;;
+changequote([,])dnl
+    *) libgomp_abs_srcdir=`cd "$srcdir" && ${PWDCMD-pwd} || echo "$srcdir"` ;;
+  esac
+  AC_CHECK_PROG(FLOCK, perl, $libgomp_abs_srcdir/testsuite/flock)
 fi
 
 AC_SUBST(SYSROOT_CFLAGS_FOR_TARGET)