diff --git a/tools/fimgfx.c b/tools/fimgfx.c
index 5042fd4..b7bd9b3 100644
--- a/tools/fimgfx.c
+++ b/tools/fimgfx.c
@@ -172,6 +172,7 @@ switch (action) {
 		
 	case Fx_halfsz0:
 		fprintf(stderr, "halfsize was not implemented\n");
+		fprintf(stderr, "see 'fimghalfsize.c'. \n");
 		return -3;
 
 	case Fx_desat:
diff --git a/tools/fimghalfsize.c b/tools/fimghalfsize.c
index b522778..32fce22 100644
--- a/tools/fimghalfsize.c
+++ b/tools/fimghalfsize.c
@@ -4,6 +4,8 @@
 #include  <stdio.h>
 #include  <unistd.h>			/* pour getopt */
 #include  <stdlib.h>
+#include  <string.h>
+
 
 #include  "../floatimg.h"