diff --git a/Libraries/gmp/build b/Libraries/gmp/build
index 27d52b8..6faae55 100755
--- a/Libraries/gmp/build
+++ b/Libraries/gmp/build
@@ -1,5 +1,7 @@
 #!/usr/bin/env modbuild
 
+SOURCE_URL="https://gmplib.org/download/$P/$P-$V.tar.bz2"
+
 pbuild::configure() {
 	"${MODULE_SRCDIR}"/configure \
 		--prefix="${PREFIX}" \