diff --git a/ChangeLog b/ChangeLog
index f33dc7990..28fc900f9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-08-11 Paulo Andrade <pcpa@gnu.org>
+
+	* lib/jit_s390x-cpu.c: Correct code checking if immediate
+	fits instruction, but using the negated value.
+
 2013-07-28 Paulo Andrade <pcpa@gnu.org>
 
 	* include/lightning/jit_s390x.h, lib/jit_s390x-cpu.c,
diff --git a/lib/jit_s390x-cpu.c b/lib/jit_s390x-cpu.c
index 527b1c1f3..b6c24795e 100644
--- a/lib/jit_s390x-cpu.c
+++ b/lib/jit_s390x-cpu.c
@@ -2377,9 +2377,9 @@ static void
 _subi(jit_state_t *_jit, jit_int32_t r0, jit_int32_t r1, jit_word_t i0)
 {
     jit_int32_t		reg;
-    if (r0 == r1 && s16_p(i0))
+    if (r0 == r1 && s16_p(-i0))
 	AGHI(r0, x16(-i0));
-    else if (s20_p(i0))
+    else if (s20_p(-i0))
 	LAY(r0, x20(-i0), 0, r1);
     else {
 	reg = jit_get_reg(jit_class_gpr);