diff --git a/src/conf_macros.m4 b/src/conf_macros.m4
index 72c0d77e94b..0164e02a1ad 100644
--- a/src/conf_macros.m4
+++ b/src/conf_macros.m4
@@ -202,7 +202,7 @@ AC_DEFUN([WITH_SYSTEMD_UNIT_DIR],
   if test x"$with_systemdunitdir" != x; then
     systemdunitdir=$with_systemdunitdir
   else
-    systemdunitdir=$($PKG_CONFIG --variable=systemdsystemunitdir systemd)
+    systemdunitdir=${prefix}$($PKG_CONFIG --variable=systemdsystemunitdir systemd)
     if test x"$systemdunitdir" = x; then
       AC_MSG_ERROR([Could not detect systemd unit directory])
     fi
@@ -222,7 +222,7 @@ AC_DEFUN([WITH_SYSTEMD_CONF_DIR],
   if test x"$with_systemdconfdir" != x; then
     systemdconfdir=$with_systemdconfdir
   else
-    systemdconfdir=$($PKG_CONFIG --variable=systemdsystemconfdir systemd)
+    systemdconfdir=${prefix}$($PKG_CONFIG --variable=systemdsystemconfdir systemd)
     if test x"$systemdconfdir" = x; then
       AC_MSG_ERROR([Could not detect systemd config directory])
     fi