diff -Nupr postgis-2.1.8~/loader/Makefile.in postgis-2.1.8/loader/Makefile.in
--- postgis-2.1.8~/loader/Makefile.in	2015-09-14 13:51:26.856353012 +0200
+++ postgis-2.1.8/loader/Makefile.in	2015-09-14 13:51:56.969353573 +0200
@@ -97,11 +97,11 @@ pgsql2shp-cli.o: pgsql2shp-cli.c pgsql2s
 
 $(PGSQL2SHP-CLI): $(SHPLIB_OBJS) pgsql2shp-core.o pgsql2shp-cli.o $(LIBLWGEOM) 
 	$(LIBTOOL) --mode=link \
-	  $(CC) $(CFLAGS) $^ $(LDFLAGS) $(ICONV_LDFLAGS) $(PGSQL_FE_LDFLAGS) $(GETTEXT_LDFLAGS) -o $@
+	  $(CC) $(CFLAGS) $^ $(LDFLAGS) $(ICONV_LDFLAGS) $(PGSQL_FE_LDFLAGS) $(GETTEXT_LDFLAGS) -lm -o $@
 
 $(SHP2PGSQL-CLI): $(SHPLIB_OBJS) shp2pgsql-core.o shp2pgsql-cli.o $(LIBLWGEOM) 
 	$(LIBTOOL) --mode=link \
-	  $(CC) $(CFLAGS) $^ -o $@ $(LDFLAGS) $(GETTEXT_LDFLAGS) $(ICONV_LDFLAGS)
+	  $(CC) $(CFLAGS) $^ -o $@ $(LDFLAGS) $(GETTEXT_LDFLAGS) $(ICONV_LDFLAGS) -lm
 
 shp2pgsql-gui.o: shp2pgsql-gui.c shp2pgsql-core.h shpcommon.h
 	$(CC) $(CFLAGS) $(GTK_CFLAGS) $(PGSQL_FE_CPPFLAGS) -o $@ -c shp2pgsql-gui.c
@@ -109,7 +109,7 @@ shp2pgsql-gui.o: shp2pgsql-gui.c shp2pgs
 $(SHP2PGSQL-GUI): $(SHPLIB_OBJS) shp2pgsql-core.o shp2pgsql-gui.o pgsql2shp-core.o $(LIBLWGEOM) $(GTK_WIN32_RES)
 	$(LIBTOOL) --mode=link \
 	  $(CC) $(CFLAGS) $(GTK_WIN32_FLAGS) $^ -o $@ \
-	  $(LDFLAGS) $(GTK_LIBS) $(ICONV_LDFLAGS) $(PGSQL_FE_LDFLAGS) $(GETTEXT_LDFLAGS)
+	  $(LDFLAGS) $(GTK_LIBS) $(ICONV_LDFLAGS) $(PGSQL_FE_LDFLAGS) $(GETTEXT_LDFLAGS) -lm
 
 installdir:
 	@mkdir -p $(DESTDIR)$(bindir)