diff --git a/src/emu/cpu/mips/r3000.c b/src/emu/cpu/mips/r3000.c
index 47fe080445d..9366100810b 100644
--- a/src/emu/cpu/mips/r3000.c
+++ b/src/emu/cpu/mips/r3000.c
@@ -496,7 +496,7 @@ offs_t r3000_device::disasm_disassemble(char *buffer, offs_t pc, const UINT8 *op
     MEMORY ACCESSORS
 ***************************************************************************/
 
-inline UINT32 r3000_device::readop(off_t pc)
+inline UINT32 r3000_device::readop(offs_t pc)
 {
 	return m_direct->read_decrypted_dword(pc);
 }
diff --git a/src/emu/cpu/mips/r3000.h b/src/emu/cpu/mips/r3000.h
index af2785b308a..07711920f3b 100644
--- a/src/emu/cpu/mips/r3000.h
+++ b/src/emu/cpu/mips/r3000.h
@@ -142,7 +142,7 @@ protected:
 		void	(r3000_device::*m_write_dword)(offs_t byteaddress, UINT32 data);
 	};
 
-	UINT32 readop(off_t pc);
+	UINT32 readop(offs_t pc);
 	UINT8 readmem(offs_t offset);
 	UINT16 readmem_word(offs_t offset);
 	UINT32 readmem_dword(offs_t offset);