diff --git a/Dockerfile.custom b/Dockerfile.custom
index 0866353..0f46c81 100644
--- a/Dockerfile.custom
+++ b/Dockerfile.custom
@@ -49,7 +49,7 @@ RUN if [ -n "$TERRAFORM_VERSION" ] ; then /scripts/install-terraform $TERRAFORM_
 
 # GraphicsMagick
 ARG GRAPHISMAGICK_VERSION
-ARG GRAPHISMAGICK_DOWNLOAD_URL=ftp://ftp.graphicsmagick.org/pub/GraphicsMagick/1.3/GraphicsMagick-${GRAPHISMAGICK_VERSION}.tar.gz
+ARG GRAPHISMAGICK_DOWNLOAD_URL=https://sourceforge.net/projects/graphicsmagick/files/graphicsmagick/${GRAPHISMAGICK_VERSION}/GraphicsMagick-${GRAPHISMAGICK_VERSION}.tar.gz
 ARG GRAPHISMAGICK_DOWNLOAD_SHA256
 RUN if [ -n "$GRAPHISMAGICK_VERSION" ]; then /scripts/install-graphicsmagick && gm version; fi