diff --git a/testscript/testdata/build.txt b/testscript/testdata/build.txt
index 1ea31c7d..a032b310 100644
--- a/testscript/testdata/build.txt
+++ b/testscript/testdata/build.txt
@@ -1,7 +1,8 @@
 [!exec:sh] skip 'sh not found in $PATH'
 
 # test that the build:tag condition works for set build tags
-[build:go1.16] exec sh -c 'exit 0'
+[build:go1.16] exec cat ok
+stdout ok
 [build:go1.17] exec sh -c 'exit 0'
 
 # test that the build:tag condition works for unset build tags