diff --git a/3rdparty/Makefile b/3rdparty/Makefile
index 4b26e753..05b0e63e 100644
--- a/3rdparty/Makefile
+++ b/3rdparty/Makefile
@@ -74,7 +74,7 @@ LIBPNGVER = 1.6.37
 LIBPNG = libpng-$(LIBPNGVER)
 LIBPNGARCH = $(LIBPNG).tar.gz
 LIBPNGURL = https://download.sourceforge.net/libpng/$(LIBPNGARCH)
-LIBPNGURLALT = ftp://ftp-osl.osuosl.org/pub/libpng/src/libpng16/$(LIBPNGARCH)
+LIBPNGURLALT = http://sourceforge.mirrorservice.org/l/project/project/li/libpng/libpng16/$(LIBPNGVER)/$(LIBPNGARCH)
 LIBPNGSHA256 = daeb2620d829575513e35fecc83f0d3791a620b9b93d800b763542ece9390fb4
 LATESTLIBPNGVER = $(shell curl -s -S http://www.libpng.org/pub/png/libpng.html | grep "current public release" | sed 's/.*libpng \([0-9.]*\).*/\1/' )
 JPEGVER = 9d