diff --git a/autoconf/ast_ext_lib.m4 b/autoconf/ast_ext_lib.m4
index 4842c3ee056e8e67d9a333000aeea0a960e8e331..8f35f4bad830fc6fbcf353dd094d3688a06af2a1 100644
--- a/autoconf/ast_ext_lib.m4
+++ b/autoconf/ast_ext_lib.m4
@@ -112,9 +112,9 @@ if test "x${PBX_$1}" != "x1" -a "${USE_$1}" != "no"; then
    # if --with-$1=DIR has been specified, use it.
    if test "x${$1_DIR}" != "x"; then
       if test -d ${$1_DIR}/lib; then
-      	 pbxlibdir="-L${$1_DIR}/lib"
+         pbxlibdir="-L${$1_DIR}/lib"
       else
-      	 pbxlibdir="-L${$1_DIR}"
+         pbxlibdir="-L${$1_DIR}"
       fi
    fi
    pbxfuncname="$3"