diff --git a/coverage.sh b/coverage.sh
index 7a84b2f..03e3796 100755
--- a/coverage.sh
+++ b/coverage.sh
@@ -1,6 +1,6 @@
 #!/bin/bash -e
 
-cargo rustc -- --test -C link-dead-code -Z profile -Z no-landing-pads
+cargo rustc --features map -- --test -C link-dead-code -Z profile -Z no-landing-pads
 
 LCOVOPTS=(
   --gcov-tool llvm-gcov