diff --git a/lang/m2/libm2/MathLib0.mod b/lang/m2/libm2/MathLib0.mod
index 15c3161cb..f3f67be6b 100644
--- a/lang/m2/libm2/MathLib0.mod
+++ b/lang/m2/libm2/MathLib0.mod
@@ -48,7 +48,7 @@ PROCEDURE entier(x: REAL): INTEGER;
 BEGIN
 	IF x < 0.0 THEN
 		i := TRUNC(-x);
-		IF FLOAT(-i) = x THEN
+		IF FLOAT(i) = -x THEN
 			RETURN -i;
 		ELSE
 			RETURN -i -1;