diff --git a/ui/build/sandbox_linux.go b/ui/build/sandbox_linux.go
index b0a6748..5b2046e 100644
--- a/ui/build/sandbox_linux.go
+++ b/ui/build/sandbox_linux.go
@@ -97,8 +97,11 @@
 			"-u", "nobody",
 			"-g", sandboxConfig.group,
 			"-R", "/",
-			"-B", sandboxConfig.srcDir,
+			// Mount tmp before srcDir
+			// srcDir is /tmp/.* in integration tests, which is a child dir of /tmp
+			// nsjail throws an error if a child dir is mounted before its parent
 			"-B", "/tmp",
+			"-B", sandboxConfig.srcDir,
 			"-B", sandboxConfig.outDir,
 		}