diff --git a/cc/sanitize.go b/cc/sanitize.go
index 5c68a96..6c38355 100644
--- a/cc/sanitize.go
+++ b/cc/sanitize.go
@@ -56,6 +56,10 @@
 		// higher number of "optimized out" stack variables.
 		// b/112437883.
 		"-instcombine-lower-dbg-declare=0",
+		// TODO(b/159343917): HWASan and GlobalISel don't play nicely, and
+		// GlobalISel is the default at -O0 on aarch64.
+		"--aarch64-enable-global-isel-at-O=-1",
+		"-fast-isel=false",
 		"-hwasan-use-after-scope=1",
 		"-dom-tree-reachability-max-bbs-to-explore=128",
 	}