diff --git a/firmware/application/touch.cpp b/firmware/application/touch.cpp
index 09f8db8f..503af80f 100644
--- a/firmware/application/touch.cpp
+++ b/firmware/application/touch.cpp
@@ -23,13 +23,7 @@
 
 namespace touch {
 
-struct Metrics {
-	const float x;
-	const float y;
-	const float r;
-};
-
-static Metrics calculate_metrics(const Frame& frame) {
+Metrics calculate_metrics(const Frame& frame) {
 	/* TODO: Yikes! M0 doesn't have floating point, so this code is
 	 * expensive! On the other hand, it seems to be working well (and
 	 * fast *enough*?), so maybe leave it alone at least for now.
diff --git a/firmware/application/touch.hpp b/firmware/application/touch.hpp
index 0402243a..31c1bd55 100644
--- a/firmware/application/touch.hpp
+++ b/firmware/application/touch.hpp
@@ -106,6 +106,14 @@ struct Frame {
 	bool touch { false };
 };
 
+struct Metrics {
+	const float x;
+	const float y;
+	const float r;
+};
+
+Metrics calculate_metrics(const Frame& frame);
+
 template<size_t N>
 class Filter {
 public: