diff --git a/tools/Makefile b/tools/Makefile
index ef8c091..6206a09 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -5,7 +5,7 @@
 #	PLEASE ! update to the 'Global.makefile' concept !
 #
 
-COPT = -Wall -fpic -g -DDEBUG_LEVEL=0 -lm
+COPT = -Wall -fpic -g -DDEBUG_LEVEL=0
 DEPS = ../floatimg.h  ../libfloatimg.a Makefile
 
 # 			----------
@@ -16,37 +16,37 @@ all:	fimg2pnm mkfimg png2fimg fimgstats fimg2png		\
 	fimghalfsize
 
 fimgstats:	fimgstats.c $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a -lm -o $@
 
 cumulfimgs:	cumulfimgs.c $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a -lm -o $@
 
 mkfimg:		mkfimg.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a -lm -o $@
 
 fimgops:		fimgops.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a -o $@
 
 fimgfx:		fimgfx.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a -lm -o $@
 
 fimghalfsize:		fimghalfsize.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a -lm -o $@
 
 fimg2pnm:	fimg2pnm.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a -lm -o $@
 
 fimg2fits:	fimg2fits.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a  -lcfitsio -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a  -lcfitsio -o $@
 
 fimg2png:	fimg2png.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -lpnglite -lz -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a -lpnglite -lz -lm -o $@
 
 fimg2text:	fimg2text.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a  -o $@ 
+	gcc $(COPT) $< ../libfloatimg.a -lm -o $@
 
 fimg2tiff:	fimg2tiff.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -ltiff -o $@
+	gcc $(COPT) $< ../libfloatimg.a -ltiff -lm -o $@
 
 #
 # this tool require an external library
@@ -61,5 +61,5 @@ addpnm2fimg:	addpnm2fimg.c  $(DEPS)
 
 # if "undefined reference to crc32" then "use -lz"
 png2fimg:	png2fimg.c  $(DEPS)
-	gcc $(COPT) $< ../libfloatimg.a -lpnglite -lz -o $@
+	gcc $(COPT) $< ../libfloatimg.a -lpnglite -lz -lm -o $@