diff --git a/tools/read-file.c b/tools/read-file.c
index a65a9890..ee35a935 100644
--- a/tools/read-file.c
+++ b/tools/read-file.c
@@ -14,6 +14,8 @@
   limitations under the License.
 */
 
+#include "config.h"
+
 #include "read-file.h"
 
 #include <sys/stat.h>