diff --git a/funcs/fimg-png.c b/funcs/fimg-png.c
index 6daa482..4de9cad 100644
--- a/funcs/fimg-png.c
+++ b/funcs/fimg-png.c
@@ -199,7 +199,7 @@ if (NULL==bytes) {
    /* compute max value */
 maximum = (double)fimg_get_maxvalue(src);
 fk = maximum / 255.0;
-fprintf(stderr, "   max values %g fk %g\n", maximum, fk);
+if (verbosity > 1) fprintf(stderr, "max val %g fk %g\n", maximum, fk);
    /* massage des pixels */
 bptr = bytes;
 for (idx=0; idx<sz; idx++) {
diff --git a/lib/Makefile b/lib/Makefile
index ea2e3d4..6280e92 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -2,7 +2,8 @@
 #	building the base library
 #
 
-COPT = -Wall -fpic -g -no-pie -DDEBUG_LEVEL=0
+COPT = -Wall -fpic -g -pg -no-pie -DDEBUG_LEVEL=0
+
 OBJS = fimg-core.o fimg-pnm.o fimg-file.o fimg-math.o	\
 	fimg-timers.o operators.o fimg-2gray.o		\
 	interpolate.o fimg-compare.o contrast.o