diff -r 2aed5418e142 -r 6008840b859e src/rules/pawn.c
--- a/src/rules/pawn.c	Sat Mar 29 14:46:33 2014 +0100
+++ b/src/rules/pawn.c	Sat Mar 29 16:53:58 2014 +0100
@@ -32,6 +32,22 @@
 
 _Bool pawn_chkrules(Board board, Move *move) {
     int8_t d = ((move->piece & COLOR_MASK) == WHITE ? -1 : 1);
+    
+    if (move->torow == (d < 0 ? 7 : 0)) {
+        if (move->promotion) {
+            uint8_t promopiece = move->promotion & PIECE_MASK;
+            if (!promopiece || promopiece == PAWN || promopiece == KING) {
+                return FALSE;
+            }
+        } else {
+            return FALSE;
+        }
+    } else {
+        if (move->promotion) {
+            return FALSE;
+        }
+    }
+    
     if (move->capture) {
         if (move->fromrow == move->torow + d && (
             move->fromfile == move->tofile + 1 ||