diff --git a/lang/m2/libm2/MathLib0.mod b/lang/m2/libm2/MathLib0.mod
index a27d29ffa..15c3161cb 100644
--- a/lang/m2/libm2/MathLib0.mod
+++ b/lang/m2/libm2/MathLib0.mod
@@ -48,7 +48,11 @@ PROCEDURE entier(x: REAL): INTEGER;
 BEGIN
 	IF x < 0.0 THEN
 		i := TRUNC(-x);
-		RETURN -i;
+		IF FLOAT(-i) = x THEN
+			RETURN -i;
+		ELSE
+			RETURN -i -1;
+		END;
 	END;
 	RETURN TRUNC(x);
 END entier;