diff --git a/src/mame/machine/apple3.cpp b/src/mame/machine/apple3.cpp
index e9e6a43a503..df3ef3b9be3 100644
--- a/src/mame/machine/apple3.cpp
+++ b/src/mame/machine/apple3.cpp
@@ -59,6 +59,10 @@
 #define ENV_PRIMARYROM  (0x02)
 #define ENV_ROMENABLE   (0x01)
 
+// 14M / 14, but with every 65th cycle stretched which we cannot reasonably emulate
+// 2 MHz mode probably has every 33rd cycle stretched but this is currently unproven.
+static constexpr XTAL APPLE2_CLOCK(1'021'800);
+
 READ8_MEMBER(apple3_state::apple3_c0xx_r)
 {
 	uint8_t result = 0xFF;
@@ -504,7 +508,7 @@ void apple3_state::apple3_update_memory()
 		logerror("apple3_update_memory(): via_0_b=0x%02x via_1_a=0x0x%02x\n", m_via_0_b, m_via_1_a);
 	}
 
-	m_maincpu->set_unscaled_clock(14.318181_MHz_XTAL / ((m_via_0_a & ENV_SLOWSPEED) ? 14 : 7));
+	m_maincpu->set_unscaled_clock(((m_via_0_a & ENV_SLOWSPEED) ? APPLE2_CLOCK : (14.318181_MHz_XTAL / 7)));
 
 	/* bank 2 (0100-01FF) */
 	if (!(m_via_0_a & ENV_STACK1XX))