diff --git a/lib/fimg-file.c b/lib/fimg-file.c
index caad379..a161280 100644
--- a/lib/fimg-file.c
+++ b/lib/fimg-file.c
@@ -68,11 +68,16 @@ FILE		*fp;
 int		foo, nbre;
 FimgFileHead	filehead;
 
-#if 1 // DEBUG_LEVEL
+#if DEBUG_LEVEL
 fprintf(stderr, ">>> %s ( %p '%s' %p %d )\n", __func__, fimg,
 						fname, pmd, notused);
 #endif
 
+if (notused) {
+	fprintf(stderr, "%s: notused must be 0, was %d\n", \
+			__func__,			notused);
+	}
+
 if (FIMG_TYPE_RGB != fimg->type) {
 	fprintf(stderr, "%s : bad type %d\n", __func__, fimg->type);
 	return -8;
@@ -147,6 +152,11 @@ fprintf(stderr, ">>> %-25s ( %p '%s' %d )\n", __func__, fimg,
 						fname, notused);
 #endif
 
+if (notused) {
+	fprintf(stderr, "%s: notused must be 0, was %d\n", \
+			__func__,			notused);
+	}
+
 if (FIMG_TYPE_RGB != fimg->type) {
 	fprintf(stderr, "%s : bad type %d\n", __func__, fimg->type);
 	return -8;