diff --git a/src/include/86box/vid_mda.h b/src/include/86box/vid_mda.h
index 37a4f6b21..ea98bef61 100644
--- a/src/include/86box/vid_mda.h
+++ b/src/include/86box/vid_mda.h
@@ -52,12 +52,12 @@ typedef struct mda_t {
 
 void    mda_init(mda_t *mda);
 void    mda_setcol(int chr, int blink, int fg, uint8_t cga_ink);
-void    mda_out(uint16_t addr, uint8_t val, void *p);
-uint8_t mda_in(uint16_t addr, void *p);
-void    mda_write(uint32_t addr, uint8_t val, void *p);
-uint8_t mda_read(uint32_t addr, void *p);
+void    mda_out(uint16_t addr, uint8_t val, void *priv);
+uint8_t mda_in(uint16_t addr, void *priv);
+void    mda_write(uint32_t addr, uint8_t val, void *priv);
+uint8_t mda_read(uint32_t addr, void *priv);
 void    mda_recalctimings(mda_t *mda);
-void    mda_poll(void *p);
+void    mda_poll(void *priv);
 
 #ifdef EMU_DEVICE_H
 extern const device_t mda_device;
diff --git a/src/video/vid_mda.c b/src/video/vid_mda.c
index 8888208e2..f743885c5 100644
--- a/src/video/vid_mda.c
+++ b/src/video/vid_mda.c
@@ -75,7 +75,7 @@ mda_out(uint16_t addr, uint8_t val, void *priv)
 uint8_t
 mda_in(uint16_t addr, void *priv)
 {
-    mda_t *mda = (mda_t *) priv;
+    const mda_t *mda = (mda_t *) priv;
 
     switch (addr) {
         case 0x3b0:
@@ -107,7 +107,7 @@ mda_write(uint32_t addr, uint8_t val, void *priv)
 uint8_t
 mda_read(uint32_t addr, void *priv)
 {
-    mda_t *mda = (mda_t *) priv;
+    const mda_t *mda = (mda_t *) priv;
 
     return mda->vram[addr & 0xfff];
 }