diff --git a/x509-parser/.frama-c/GNUmakefile b/x509-parser/.frama-c/GNUmakefile
index 4a5b3549e101572fec287856eccb944ccd5693cd..3e26f813a2cc90cd34226cbf48867c7b9abc689d 100644
--- a/x509-parser/.frama-c/GNUmakefile
+++ b/x509-parser/.frama-c/GNUmakefile
@@ -47,6 +47,10 @@ EVAFLAGS    += \
 				      parse_x509_AlgorithmIdentifier:200" \
   -eva-warn-undefined-pointer-comparison none \
 
+## WP-specific flags
+# Tools versions
+# - Why3 1.4.0
+# - Alt-Ergo 2.4.0
 WPFLAGS += \
   -wp-par 12 \
   -wp-timeout 15 \