diff --git a/pkgs/build-support/setup-hooks/set-source-date-epoch-to-latest.sh b/pkgs/build-support/setup-hooks/set-source-date-epoch-to-latest.sh
index 9e325106f821..fe3458cd21e8 100644
--- a/pkgs/build-support/setup-hooks/set-source-date-epoch-to-latest.sh
+++ b/pkgs/build-support/setup-hooks/set-source-date-epoch-to-latest.sh
@@ -27,5 +27,7 @@ updateSourceDateEpoch() {
 postUnpackHooks+=(_updateSourceDateEpochFromSourceRoot)
 
 _updateSourceDateEpochFromSourceRoot() {
-    updateSourceDateEpoch "$sourceRoot"
+    if [ -n "$sourceRoot" ]; then
+        updateSourceDateEpoch "$sourceRoot"
+    fi
 }