diff --git a/libs/widgets/ardour_spacer.cc b/libs/widgets/ardour_spacer.cc
index 6058c89646..d71fa120ac 100644
--- a/libs/widgets/ardour_spacer.cc
+++ b/libs/widgets/ardour_spacer.cc
@@ -17,6 +17,8 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <algorithm>
+
 #include "widgets/ardour_spacer.h"
 
 using namespace ArdourWidgets;
@@ -31,13 +33,13 @@ ArdourScalingSpacer::ArdourScalingSpacer (int natural_width, int natural_height)
 
 ArdourVSpacer::ArdourVSpacer (float r)
 	: CairoWidget ()
-	, ratio (r)
+	, _ratio (std::min (1.f, r))
 {
 }
 
 ArdourHSpacer::ArdourHSpacer (float r)
 	: CairoWidget ()
-	, ratio (r)
+	, _ratio (std::min (1.f, r))
 {
 }
 
diff --git a/libs/widgets/widgets/ardour_spacer.h b/libs/widgets/widgets/ardour_spacer.h
index 7d078c6e97..cf8a03368a 100644
--- a/libs/widgets/widgets/ardour_spacer.h
+++ b/libs/widgets/widgets/ardour_spacer.h
@@ -60,9 +60,13 @@ public:
 protected:
 	void render (Cairo::RefPtr<Cairo::Context> const& ctx, cairo_rectangle_t*) {
 
+		if (_ratio < 0) {
+			return;
+		}
+
 		float height = get_height();
 
-		float h = height * ratio;
+		float h = height * _ratio;
 		float t = .5f * (height - h);
 		ctx->rectangle (0, t, 1, h);
 		uint32_t c = UIConfigurationBase::instance().color ("neutral:backgroundest");
@@ -76,7 +80,8 @@ protected:
 		CairoWidget::on_size_request (req);
 	}
 
-	float ratio;
+private:
+	float _ratio;
 };
 
 class LIBWIDGETS_API ArdourHSpacer : public CairoWidget
@@ -87,9 +92,13 @@ public:
 protected:
 	void render (Cairo::RefPtr<Cairo::Context> const& ctx, cairo_rectangle_t*) {
 
+		if (_ratio < 0) {
+			return;
+		}
+
 		float width = get_width();
 
-		float w = width * ratio;
+		float w = width * _ratio;
 		float t = .5f * (width - w);
 		ctx->rectangle (t, 0, w, 1);
 		uint32_t c = UIConfigurationBase::instance().color ("neutral:backgroundest");
@@ -103,7 +112,8 @@ protected:
 		CairoWidget::on_size_request (req);
 	}
 
-	float ratio;
+private:
+	float _ratio;
 };
 
 class LIBWIDGETS_API ArdourDropShadow : public CairoWidget