diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index 4e816c68c7..d80b0adc6c 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -798,6 +798,8 @@ static void __cpu_ppc_store_decr(PowerPCCPU *cpu, uint64_t *nextp,
     int64_t signed_decr;
 
     /* Truncate value to decr_width and sign extend for simplicity */
+    value = extract64(value, 0, nr_bits);
+    decr = extract64(decr, 0, nr_bits);
     signed_value = sextract64(value, 0, nr_bits);
     signed_decr = sextract64(decr, 0, nr_bits);