diff --git a/configure b/configure
index 06f7bcc..c9a0d34 100755
--- a/configure
+++ b/configure
@@ -17901,7 +17901,7 @@ if test "x$no_ft" != xyes; then
    EXTRALIBS="$EXTRALIBS $FT2_LIBS"
    EXTRACFLAGS="$EXTRACFLAGS $FT2_CFLAGS"
 fi
-if test x"SRC_FONT" = "x"; then
+if test x"$SRC_FONT" = "x"; then
   as_fn_error $? "\"*** No font device available ***\"" "$LINENO" 5;
 fi
 
diff --git a/configure.ac b/configure.ac
index 56b0a49..d5c2ea2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -707,7 +707,7 @@ if test "x$no_ft" != xyes; then
 fi
 dnl
 dnl check null
-if test x"SRC_FONT" = "x"; then
+if test x"$SRC_FONT" = "x"; then
   AC_MSG_ERROR("*** No font device available ***");
 fi
 AC_SUBST(SRC_FONT)