diff --git a/src/acc3221.c b/src/acc3221.c
index 38c6fa9..2b3fb8a 100644
--- a/src/acc3221.c
+++ b/src/acc3221.c
@@ -55,7 +55,7 @@ static void acc3221_write(uint16_t addr, uint8_t val, void *p)
 //                                        pclog("COM1 addr %03x IRQ 3\n", addr);
                                         serial1_set(addr, 3);
                                 }
-                                else if ((acc3221.regs[0xde] & REG_DE_SIRQ4_SOURCE) == REG_DE_SIRQ3_SERIAL1)
+                                else if ((acc3221.regs[0xde] & REG_DE_SIRQ4_SOURCE) == REG_DE_SIRQ4_SERIAL1)
                                 {
 //                                        pclog("COM1 addr %03x IRQ 4\n", addr);
                                         serial1_set(addr, 4);
@@ -76,7 +76,7 @@ static void acc3221_write(uint16_t addr, uint8_t val, void *p)
 //                                        pclog("COM2 addr %03x IRQ 3\n", addr);
                                         serial2_set(addr, 3);
                                 }
-                                else if ((acc3221.regs[0xde] & REG_DE_SIRQ4_SOURCE) == REG_DE_SIRQ3_SERIAL2)
+                                else if ((acc3221.regs[0xde] & REG_DE_SIRQ4_SOURCE) == REG_DE_SIRQ4_SERIAL2)
                                 {
 //                                        pclog("COM2 addr %03x IRQ 4\n", addr);
                                         serial2_set(addr, 4);