diff --git a/src/core/dune b/src/core/dune
index e5c561a3..6ec93b3a 100644
--- a/src/core/dune
+++ b/src/core/dune
@@ -4,7 +4,7 @@
   (public_name msat)
   (libraries sequence)
   (synopsis "core data structures and algorithms for msat")
-  (flags :standard -w +a-4-42-44-48-50-58-32-60@8 -color always -safe-string)
+  (flags :standard -warn-error -3 -w +a-4-42-44-48-50-58-32-60@8 -color always -safe-string)
   (ocamlopt_flags :standard -O3 -bin-annot
                   -unbox-closures -unbox-closures-factor 20)
   )
diff --git a/src/main/dune b/src/main/dune
index 7b96abd7..bb0eb7d4 100644
--- a/src/main/dune
+++ b/src/main/dune
@@ -4,7 +4,7 @@
   (name main)
   ;(package msat)
   (libraries containers msat msat_sat msat.backend)
-  (flags :standard -w +a-4-42-44-48-50-58-32-60@8 -color always -safe-string -open Msat)
+  (flags :standard -warn-error -3 -w +a-4-42-44-48-50-58-32-60@8 -color always -safe-string -open Msat)
   (ocamlopt_flags :standard -O3 -color always
                   -unbox-closures -unbox-closures-factor 20)
   )
diff --git a/src/sat/dune b/src/sat/dune
index b5940271..624b2a57 100644
--- a/src/sat/dune
+++ b/src/sat/dune
@@ -4,7 +4,7 @@
   (public_name msat.sat)
   (synopsis "purely boolean interface to Msat")
   (libraries msat)
-  (flags :standard -w +a-4-42-44-48-50-58-32-60@8 -color always -safe-string -open Msat)
+  (flags :standard -warn-error -3 -w +a-4-42-44-48-50-58-32-60@8 -color always -safe-string -open Msat)
   (ocamlopt_flags :standard -O3 -color always
                   -unbox-closures -unbox-closures-factor 20)
   )