diff --git a/src/include/86box/snd_sb_dsp.h b/src/include/86box/snd_sb_dsp.h
index 568b02f47..bf9ceab53 100644
--- a/src/include/86box/snd_sb_dsp.h
+++ b/src/include/86box/snd_sb_dsp.h
@@ -140,6 +140,8 @@ typedef struct sb_dsp_t {
 
     uint8_t azt_eeprom[AZTECH_EEPROM_SIZE]; /* the eeprom in the Aztech cards is attached to the DSP */
 
+    uint8_t ess_regs[256]; /* ESS registers. */
+
     mpu_t *mpu;
 } sb_dsp_t;
 
diff --git a/src/sound/snd_sb_dsp.c b/src/sound/snd_sb_dsp.c
index d94faa29e..79415ac5b 100644
--- a/src/sound/snd_sb_dsp.c
+++ b/src/sound/snd_sb_dsp.c
@@ -135,6 +135,8 @@ sb_dsp_log(const char *fmt, ...)
 #    define sb_dsp_log(fmt, ...)
 #endif
 
+#define ESSreg(reg) (dsp)->ess_regs[reg - 0xA0]
+
 static __inline double
 sinc(double x)
 {