diff --git a/modules/src/flt_arith/flt_ar2flt.c b/modules/src/flt_arith/flt_ar2flt.c
index c1cb7b2a4..4fe418674 100644
--- a/modules/src/flt_arith/flt_ar2flt.c
+++ b/modules/src/flt_arith/flt_ar2flt.c
@@ -21,10 +21,22 @@ flt_arith2flt(n, e, uns)
 	}
 	else	e->flt_sign = 0;
 	if (sizeof(arith) == 4) {
-		e->m1 = n; e->m2 = 0;
-	} else {
-		e->m1 = (n >> (sizeof(arith)*8 - 32)) & 0xFFFFFFFF;
-		e->m2 = n << 32;
+		if (n < 0) {
+			e->m1 = 1; e->m2 = 0;
+		}
+		else {
+			e->m1 = 0; e->m2 = n;
+		}
+	}
+	else {
+		if (n < 0) {
+			e->m2 = 0;
+			e->m1 = (1 << (sizeof(arith)*8-32));
+		}
+		else {
+			e->m2 = n & 0xffffffffL;
+			e->m1 = (n >> 32);
+		}
 	}
 	if (n == 0) {
 		e->flt_exp = 0;