diff --git a/eclair/utils.sh b/eclair/utils.sh
index f79e198..790081e 100644
--- a/eclair/utils.sh
+++ b/eclair/utils.sh
@@ -29,6 +29,9 @@
     # ECLAIR binary data directory and workspace.
     export ECLAIR_DATA_DIR="${ECLAIR_OUTPUT_DIR}/.data"
 
+    # Destination file for the ECLAIR diagnostics.
+    export ECLAIR_DIAGNOSTICS_OUTPUT="${ECLAIR_OUTPUT_DIR}/DIAGNOSTICS.txt"
+
     PROJECT_ECD="${ECLAIR_OUTPUT_DIR}/PROJECT.ecd"
 }