diff --git a/srcpkgs/ion/template b/srcpkgs/ion/template
index 254fdcb1f42..06edd7bc01e 100644
--- a/srcpkgs/ion/template
+++ b/srcpkgs/ion/template
@@ -14,6 +14,8 @@ checksum=8ab295c5ff40de6b7a8dd93ee8d417b6e884f2b66b628409e4cd9345d70e9c00
 register_shell="/bin/ion"
 
 pre_build() {
+	# cannot divide `usize` by `u32`
+	cargo update --package lexical-core:0.7.4 --precise 0.7.6
 	echo ${_githash} > git_revision.txt
 }