diff --git a/Makefile b/Makefile
index 7fbfd41..1747b22 100644
--- a/Makefile
+++ b/Makefile
@@ -286,7 +286,7 @@ memcheck: targets
 ##################################### test binaries
 .PHONY: testing test
 
-TEST          :=piece-test fen-test bitboard-test movegen-test attack-test
+TEST          := piece-test fen-test bitboard-test movegen-test attack-test movedo-test
 
 PIECE_OBJS    := piece.o
 FEN_OBJS      := fen.o position.o piece.o bitboard.o board.o hyperbola-quintessence.o \
@@ -297,6 +297,8 @@ MOVEGEN_OBJS  := fen.o position.o piece.o bitboard.o board.o hyperbola-quintesse
 	attack.o move.o move-gen.o
 ATTACK_OBJS   := fen.o position.o piece.o bitboard.o board.o hyperbola-quintessence.o \
 	 attack.o move.o move-gen.o
+MOVEDO_OBJS   := fen.o position.o piece.o bitboard.o board.o hyperbola-quintessence.o \
+	 attack.o move.o move-gen.o move-do.o
 
 TEST          := $(addprefix $(BINDIR)/,$(TEST))
 
@@ -305,6 +307,7 @@ FEN_OBJS      := $(addprefix $(OBJDIR)/,$(FEN_OBJS))
 BB_OBJS       := $(addprefix $(OBJDIR)/,$(BB_OBJS))
 MOVEGEN_OBJS  := $(addprefix $(OBJDIR)/,$(MOVEGEN_OBJS))
 ATTACK_OBJS   := $(addprefix $(OBJDIR)/,$(ATTACK_OBJS))
+MOVEDO_OBJS   := $(addprefix $(OBJDIR)/,$(MOVEDO_OBJS))
 
 test:
 	echo TEST=$(TEST)
@@ -332,6 +335,10 @@ bin/attack-test: test/attack-test.c test/common-test.h $(ATTACK_OBJS)
 	@echo compiling $@ test executable.
 	@$(CC) $(ALL_CFLAGS) $< $(ATTACK_OBJS) $(ALL_LDFLAGS) -o $@
 
+bin/movedo-test: test/movedo-test.c test/common-test.h $(MOVEDO_OBJS)
+	@echo compiling $@ test executable.
+	@$(CC) $(ALL_CFLAGS) $< $(MOVEDO_OBJS) $(ALL_LDFLAGS) -o $@
+
 ##################################### Makefile debug
 .PHONY: showflags wft
 
diff --git a/test/common-test.h b/test/common-test.h
index 3064379..9486ca5 100644
--- a/test/common-test.h
+++ b/test/common-test.h
@@ -14,11 +14,12 @@
 #include <stdio.h>
 #include "chessdefs.h"
 /* when below FENs are in a struct with selection per test */
-#define NOTEST   0
-#define FEN      1
-#define BITBOARD 2
-#define MOVEGEN  4
-#define ATTACK   8
+#define NOTEST      0
+#define FEN         1
+#define BITBOARD    2
+#define MOVEGEN     4
+#define ATTACK      8
+#define MOVEDO     16
 
 struct fentest {
     uint modules;
@@ -367,7 +368,18 @@ struct fentest {
       "illegal, SF crash",
       "2r1k3/3P4/8/8/8/8/8/4K3 w - - 0 1"
     },
-
+    { MOVEDO,
+      "simple movedo/undo: only 2 W knights",
+      "8/1k6/8/8/8/8/6K1/1NN5 w - - 0 1"
+    },
+    { MOVEDO,
+      "simple movedo/undo: only 2 W knights",
+      "8/1k6/8/8/8/8/6K1/1NN5 w - - 0 1"
+    },
+    { MOVEDO,
+      "simple movedo/undo: only 2 W knights",
+      "5n2/1k6/8/8/5K2/8/P7/1N6 w - - 0 1"
+    },
     { 0, NULL, NULL }
 };
 
diff --git a/test/movedo-test.c b/test/movedo-test.c
new file mode 100644
index 0000000..c498514
--- /dev/null
+++ b/test/movedo-test.c
@@ -0,0 +1,80 @@
+/* movedo-test.c - basic movedo/undo tests.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "chessdefs.h"
+#include "fen.h"
+#include "position.h"
+#include "move.h"
+#include "move-do.h"
+#include "move-gen.h"
+
+#include "common-test.h"
+
+int main(int __unused ac, __unused char**av)
+{
+    int i = 1;
+    char *fen, movebuf[8];;
+    pos_t *pos, *savepos;
+    move_t move;
+
+    setlinebuf(stdout);                           /* line-buffered stdout */
+
+    bitboard_init();
+    hyperbola_init();
+
+    while ((fen = next_fen(MOVEGEN | MOVEDO))) {
+        if (!(pos = fen2pos(NULL, fen))) {
+            printf("wrong fen %d: [%s]\n", i, fen);
+            continue;
+        }
+        pos_gen_pseudomoves(pos);
+        savepos = pos_dup(pos);
+        if (pos_cmp(pos, savepos) != true) {
+            printf("*** positions differ 1\n");
+            exit(0);
+        }
+        int tmp = 0, j = 1;
+        while ((move = pos_next_legal(pos, &tmp)) != MOVE_NONE) {
+            state_t state;
+
+            pos_print(pos);
+            printf("i=%d j=%d  turn=%d move=[%s]\n", i, j, pos->turn,
+                   move_str(movebuf, move, 0));
+            //move_p
+            move_do(pos, move, &state);
+            pos_print(pos);
+            fflush(stdout);
+            pos_check(pos, true);
+            printf("%d/%d move_do check ok\n", i, j);
+            move_undo(pos, move, &state);
+            if (pos_cmp(pos, savepos) != true) {
+                printf("*** positions differ 2\n");
+                exit(0);
+            }
+            fflush(stdout);
+            pos_check(pos, true);
+            printf("%d/%d move_undo check ok\n", i, j);
+
+            if (j++ == 1000)
+                exit(0);
+        }
+        pos_del(savepos);
+        pos_del(pos);
+        i++;
+    }
+    return 0;
+}