diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c
index e41cb63daa..bf4b781393 100644
--- a/hw/i2c/bitbang_i2c.c
+++ b/hw/i2c/bitbang_i2c.c
@@ -26,13 +26,19 @@ do { printf("bitbang_i2c: " fmt , ## __VA_ARGS__); } while (0)
 #define DPRINTF(fmt, ...) do {} while(0)
 #endif
 
+static void bitbang_i2c_set_state(bitbang_i2c_interface *i2c,
+                                  bitbang_i2c_state state)
+{
+    i2c->state = state;
+}
+
 static void bitbang_i2c_enter_stop(bitbang_i2c_interface *i2c)
 {
     DPRINTF("STOP\n");
     if (i2c->current_addr >= 0)
         i2c_end_transfer(i2c->bus);
     i2c->current_addr = -1;
-    i2c->state = STOPPED;
+    bitbang_i2c_set_state(i2c, STOPPED);
 }
 
 /* Set device data pin.  */
@@ -69,7 +75,7 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
         if (level == 0) {
             DPRINTF("START\n");
             /* START condition.  */
-            i2c->state = SENDING_BIT7;
+            bitbang_i2c_set_state(i2c, SENDING_BIT7);
             i2c->current_addr = -1;
         } else {
             /* STOP condition.  */
@@ -96,7 +102,7 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
     case SENDING_BIT7 ... SENDING_BIT0:
         i2c->buffer = (i2c->buffer << 1) | data;
         /* will end up in WAITING_FOR_ACK */
-        i2c->state++; 
+        bitbang_i2c_set_state(i2c, i2c->state + 1);
         return bitbang_i2c_ret(i2c, 1);
 
     case WAITING_FOR_ACK:
@@ -117,13 +123,14 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
              * device we were sending to decided to NACK us).
              */
             DPRINTF("Got NACK\n");
+            bitbang_i2c_set_state(i2c, SENT_NACK);
             bitbang_i2c_enter_stop(i2c);
             return bitbang_i2c_ret(i2c, 1);
         }
         if (i2c->current_addr & 1) {
-            i2c->state = RECEIVING_BIT7;
+            bitbang_i2c_set_state(i2c, RECEIVING_BIT7);
         } else {
-            i2c->state = SENDING_BIT7;
+            bitbang_i2c_set_state(i2c, SENDING_BIT7);
         }
         return bitbang_i2c_ret(i2c, 0);
     }
@@ -134,18 +141,18 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
     case RECEIVING_BIT6 ... RECEIVING_BIT0:
         data = i2c->buffer >> 7;
         /* will end up in SENDING_ACK */
-        i2c->state++;
+        bitbang_i2c_set_state(i2c, i2c->state + 1);
         i2c->buffer <<= 1;
         return bitbang_i2c_ret(i2c, data);
 
     case SENDING_ACK:
-        i2c->state = RECEIVING_BIT7;
         if (data != 0) {
             DPRINTF("NACKED\n");
-            i2c->state = SENT_NACK;
+            bitbang_i2c_set_state(i2c, SENT_NACK);
             i2c_nack(i2c->bus);
         } else {
             DPRINTF("ACKED\n");
+            bitbang_i2c_set_state(i2c, RECEIVING_BIT7);
         }
         return bitbang_i2c_ret(i2c, 1);
     }