diff --git a/hw/i2c/pmbus_device.c b/hw/i2c/pmbus_device.c
index ff644c1d4a..8cb9db0f80 100644
--- a/hw/i2c/pmbus_device.c
+++ b/hw/i2c/pmbus_device.c
@@ -89,16 +89,16 @@ void pmbus_send_string(PMBusDevice *pmdev, const char *data)
 }
 
 
-static uint64_t pmbus_receive_uint(const uint8_t *buf, uint8_t len)
+static uint64_t pmbus_receive_uint(PMBusDevice *pmdev)
 {
     uint64_t ret = 0;
 
     /* Exclude command code from return value */
-    buf++;
-    len--;
+    pmdev->in_buf++;
+    pmdev->in_buf_len--;
 
-    for (int i = len - 1; i >= 0; i--) {
-        ret = ret << 8 | buf[i];
+    for (int i = pmdev->in_buf_len - 1; i >= 0; i--) {
+        ret = ret << 8 | pmdev->in_buf[i];
     }
     return ret;
 }
@@ -110,7 +110,7 @@ uint8_t pmbus_receive8(PMBusDevice *pmdev)
                       "%s: length mismatch. Expected 1 byte, got %d bytes\n",
                       __func__, pmdev->in_buf_len - 1);
     }
-    return pmbus_receive_uint(pmdev->in_buf, pmdev->in_buf_len);
+    return pmbus_receive_uint(pmdev);
 }
 
 uint16_t pmbus_receive16(PMBusDevice *pmdev)
@@ -120,7 +120,7 @@ uint16_t pmbus_receive16(PMBusDevice *pmdev)
                       "%s: length mismatch. Expected 2 bytes, got %d bytes\n",
                       __func__, pmdev->in_buf_len - 1);
     }
-    return pmbus_receive_uint(pmdev->in_buf, pmdev->in_buf_len);
+    return pmbus_receive_uint(pmdev);
 }
 
 uint32_t pmbus_receive32(PMBusDevice *pmdev)
@@ -130,7 +130,7 @@ uint32_t pmbus_receive32(PMBusDevice *pmdev)
                       "%s: length mismatch. Expected 4 bytes, got %d bytes\n",
                       __func__, pmdev->in_buf_len - 1);
     }
-    return pmbus_receive_uint(pmdev->in_buf, pmdev->in_buf_len);
+    return pmbus_receive_uint(pmdev);
 }
 
 uint64_t pmbus_receive64(PMBusDevice *pmdev)
@@ -140,7 +140,7 @@ uint64_t pmbus_receive64(PMBusDevice *pmdev)
                       "%s: length mismatch. Expected 8 bytes, got %d bytes\n",
                       __func__, pmdev->in_buf_len - 1);
     }
-    return pmbus_receive_uint(pmdev->in_buf, pmdev->in_buf_len);
+    return pmbus_receive_uint(pmdev);
 }
 
 static uint8_t pmbus_out_buf_pop(PMBusDevice *pmdev)