diff --git a/src/xrt/auxiliary/tracking/t_calibration.cpp b/src/xrt/auxiliary/tracking/t_calibration.cpp
index 03e5ad0e4..46437bf18 100644
--- a/src/xrt/auxiliary/tracking/t_calibration.cpp
+++ b/src/xrt/auxiliary/tracking/t_calibration.cpp
@@ -172,7 +172,7 @@ process_frame_yuyv(class Calibration &c, struct xrt_frame *xf)
 	int half_w = w / 2;
 	int h = (int)xf->height;
 
-	class t_frame_yuyv f = {};
+	struct t_frame_yuyv f = {};
 
 	f.data_half = cv::Mat(h, half_w, CV_8UC4, xf->data, xf->stride);
 	f.data_full = cv::Mat(h, w, CV_8UC2, xf->data, xf->stride);
@@ -192,7 +192,7 @@ process_frame_yuyv(class Calibration &c, struct xrt_frame *xf)
 extern "C" void
 t_calibration_frame(struct xrt_frame_sink *xsink, struct xrt_frame *xf)
 {
-	auto &c = *(struct Calibration *)xsink;
+	auto &c = *(class Calibration *)xsink;
 
 #if 0
 	if (xf->stereo_format != XRT_FS_STEREO_SBS) {
diff --git a/src/xrt/auxiliary/tracking/t_debug_hsv_filter.cpp b/src/xrt/auxiliary/tracking/t_debug_hsv_filter.cpp
index 0bef3f110..382b9e698 100644
--- a/src/xrt/auxiliary/tracking/t_debug_hsv_filter.cpp
+++ b/src/xrt/auxiliary/tracking/t_debug_hsv_filter.cpp
@@ -77,7 +77,7 @@ t_debug_hsv_filter_frame3(struct xrt_frame_sink *xsink, struct xrt_frame *xf)
 extern "C" void
 t_debug_hsv_filter_frame(struct xrt_frame_sink *xsink, struct xrt_frame *xf)
 {
-	auto &d = *(struct DebugHSV *)xsink;
+	auto &d = *(class DebugHSV *)xsink;
 
 	d.sink->push_frame(d.sink, xf);
 	d.passthrough->push_frame(d.passthrough, xf);
diff --git a/src/xrt/auxiliary/tracking/t_debug_hsv_picker.cpp b/src/xrt/auxiliary/tracking/t_debug_hsv_picker.cpp
index 4f07b6a25..24ce9a82e 100644
--- a/src/xrt/auxiliary/tracking/t_debug_hsv_picker.cpp
+++ b/src/xrt/auxiliary/tracking/t_debug_hsv_picker.cpp
@@ -192,7 +192,7 @@ on_high_V_thresh_trackbar(int, void *)
 extern "C" void
 t_debug_hsv_picker_frame(struct xrt_frame_sink *xsink, struct xrt_frame *xf)
 {
-	auto &d = *(struct DebugHSVPicker *)xsink;
+	auto &d = *(class DebugHSVPicker *)xsink;
 
 	process_frame(d, xf);
 
diff --git a/src/xrt/auxiliary/tracking/t_debug_hsv_viewer.cpp b/src/xrt/auxiliary/tracking/t_debug_hsv_viewer.cpp
index cd01d7d18..9c6ce86a5 100644
--- a/src/xrt/auxiliary/tracking/t_debug_hsv_viewer.cpp
+++ b/src/xrt/auxiliary/tracking/t_debug_hsv_viewer.cpp
@@ -148,7 +148,7 @@ process_frame(DebugHSV &d, struct xrt_frame *xf)
 extern "C" void
 t_debug_hsv_viewer_frame(struct xrt_frame_sink *xsink, struct xrt_frame *xf)
 {
-	auto &d = *(struct DebugHSV *)xsink;
+	auto &d = *(class DebugHSV *)xsink;
 
 	process_frame(d, xf);