diff --git a/src/add-ons/accelerants/nvidia/engine/nv_i2c.c b/src/add-ons/accelerants/nvidia/engine/nv_i2c.c
index 3594629d6b..e119acb5af 100644
--- a/src/add-ons/accelerants/nvidia/engine/nv_i2c.c
+++ b/src/add-ons/accelerants/nvidia/engine/nv_i2c.c
@@ -171,6 +171,9 @@ static uint8 RXBit (uint8 BusNR)
 
 void i2c_bstart (uint8 BusNR)
 {
+	/* enable access to primary head */
+	set_crtc_owner(0);
+
 	/* make sure SDA is high */
 	OutSDA(BusNR, true);
 	snooze(3);
@@ -190,6 +193,9 @@ void i2c_bstart (uint8 BusNR)
 
 void i2c_bstop (uint8 BusNR)
 {
+	/* enable access to primary head */
+	set_crtc_owner(0);
+
 	/* make sure SDA is low */
 	OutSDA(BusNR, false);
 	snooze(3);
@@ -263,6 +269,9 @@ status_t i2c_init(void)
 
 	LOG(4,("I2C: searching for wired I2C buses...\n"));
 
+	/* enable access to primary head */
+	set_crtc_owner(0);
+
 	/* preset no board wired buses */
 	si->ps.i2c_bus0 = false;
 	si->ps.i2c_bus1 = false;