diff --git a/puer.c b/puer.c
index 4682d74..ec8d4c5 100644
--- a/puer.c
+++ b/puer.c
@@ -200,8 +200,10 @@ void finalize_hash(struct hashstate *state, unsigned char hash[32]) {
 	}
 
 	// Add the number of bits, and do one last compression
-	word2bytes(&state->buffer[state->length+=4], state->totalbits>>32);
-	word2bytes(&state->buffer[state->length+=4], state->totalbits & 0xffffffffUL);
+	word2bytes(&state->buffer[state->length], state->totalbits>>32);
+	state->length += 4;
+	word2bytes(&state->buffer[state->length], state->totalbits & 0xffffffffUL);
+	state->length += 4;
 	compress_hash(state);
 
 	// Extract the hash state