diff --git a/src/xrt/auxiliary/vive/vive_calibration.c b/src/xrt/auxiliary/vive/vive_calibration.c
index 3a993da70..04a22b2b6 100644
--- a/src/xrt/auxiliary/vive/vive_calibration.c
+++ b/src/xrt/auxiliary/vive/vive_calibration.c
@@ -228,8 +228,8 @@ vive_get_slam_cams_calib(const struct vive_config *d,
 	*out_calib1 = calib1;
 }
 
-struct t_imu_calibration
-vive_get_imu_calibration(const struct vive_config *d)
+void
+vive_get_imu_calibration(const struct vive_config *d, struct t_imu_calibration *out_calib)
 {
 
 	struct xrt_vec3 ab = d->imu.acc_bias;
@@ -253,15 +253,18 @@ vive_get_imu_calibration(const struct vive_config *d)
 	            .noise_std = {0.000282, 0.000282, 0.000282},
 	        },
 	};
-	return calib;
+
+	*out_calib = calib;
 }
 
-struct t_slam_imu_calibration
-vive_get_slam_imu_calibration(const struct vive_config *d)
+void
+vive_get_slam_imu_calibration(const struct vive_config *d, struct t_slam_imu_calibration *out_calib)
 {
 	struct t_slam_imu_calibration calib;
 	const int IMU_FREQUENCY = 1000;
-	calib.base = vive_get_imu_calibration(d);
+
+	vive_get_imu_calibration(d, &calib.base);
 	calib.frequency = IMU_FREQUENCY;
-	return calib;
+
+	*out_calib = calib;
 }
diff --git a/src/xrt/auxiliary/vive/vive_calibration.h b/src/xrt/auxiliary/vive/vive_calibration.h
index b927584d9..dfe81ab45 100644
--- a/src/xrt/auxiliary/vive/vive_calibration.h
+++ b/src/xrt/auxiliary/vive/vive_calibration.h
@@ -46,16 +46,16 @@ vive_get_slam_cams_calib(const struct vive_config *d,
  *
  * @ingroup drv_vive
  */
-struct t_imu_calibration
-vive_get_imu_calibration(const struct vive_config *d);
+void
+vive_get_imu_calibration(const struct vive_config *d, struct t_imu_calibration *out_calib);
 
 /*!
  * Get a @ref t_slam_imu_calibration for the IMU.
  *
  * @ingroup drv_vive
  */
-struct t_slam_imu_calibration
-vive_get_slam_imu_calibration(const struct vive_config *d);
+void
+vive_get_slam_imu_calibration(const struct vive_config *d, struct t_slam_imu_calibration *out_calib);
 
 
 #ifdef __cplusplus
diff --git a/src/xrt/targets/common/target_builder_lighthouse.c b/src/xrt/targets/common/target_builder_lighthouse.c
index 2f20bc622..f9d14225b 100644
--- a/src/xrt/targets/common/target_builder_lighthouse.c
+++ b/src/xrt/targets/common/target_builder_lighthouse.c
@@ -385,7 +385,7 @@ valve_index_setup_visual_trackers(struct lighthouse_system *lhs,
 	// SLAM calibration
 	lhs->slam_calib.cam_count = 2;
 	vive_get_slam_cams_calib(lhs->hmd_config, &lhs->slam_calib.cams[0], &lhs->slam_calib.cams[1]);
-	lhs->slam_calib.imu = vive_get_slam_imu_calibration(lhs->hmd_config);
+	vive_get_slam_imu_calibration(lhs->hmd_config, &lhs->slam_calib.imu);
 
 	// Initialize SLAM tracker
 	struct xrt_slam_sinks *slam_sinks = NULL;