diff --git a/src/libslic3r/MeasureUtils.hpp b/src/libslic3r/MeasureUtils.hpp
index 4f84624eac..34fea9855c 100644
--- a/src/libslic3r/MeasureUtils.hpp
+++ b/src/libslic3r/MeasureUtils.hpp
@@ -93,7 +93,7 @@ protected:
     std::vector<double> m_coefficient;
 };
 
-Polynomial1 operator * (const Polynomial1& p0, const Polynomial1& p1)
+inline Polynomial1 operator * (const Polynomial1& p0, const Polynomial1& p1)
 {
     const uint32_t p0Degree = p0.GetDegree();
     const uint32_t p1Degree = p1.GetDegree();
@@ -107,7 +107,7 @@ Polynomial1 operator * (const Polynomial1& p0, const Polynomial1& p1)
     return result;
 }
 
-Polynomial1 operator + (const Polynomial1& p0, const Polynomial1& p1)
+inline Polynomial1 operator + (const Polynomial1& p0, const Polynomial1& p1)
 {
     const uint32_t p0Degree = p0.GetDegree();
     const uint32_t p1Degree = p1.GetDegree();
@@ -136,7 +136,7 @@ Polynomial1 operator + (const Polynomial1& p0, const Polynomial1& p1)
     }
 }
 
-Polynomial1 operator - (const Polynomial1& p0, const Polynomial1& p1)
+inline Polynomial1 operator - (const Polynomial1& p0, const Polynomial1& p1)
 {
     const uint32_t p0Degree = p0.GetDegree();
     const uint32_t p1Degree = p1.GetDegree();
@@ -165,7 +165,7 @@ Polynomial1 operator - (const Polynomial1& p0, const Polynomial1& p1)
     }
 }
 
-Polynomial1 operator * (double scalar, const Polynomial1& p)
+inline Polynomial1 operator * (double scalar, const Polynomial1& p)
 {
     const uint32_t degree = p.GetDegree();
     Polynomial1 result(degree);
@@ -354,7 +354,7 @@ public:
 // the maximum absolute component occurs at index i, then the orthogonal
 // vector U has u[i] = v[i+1], u[i+1] = -v[i], and all other components
 // zero.  The index addition i+1 is computed modulo N.
-Vec3d get_orthogonal(const Vec3d& v, bool unitLength)
+inline Vec3d get_orthogonal(const Vec3d& v, bool unitLength)
 {
     double cmax = std::fabs(v[0]);
     int32_t imax = 0;
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoMeasure.cpp b/src/slic3r/GUI/Gizmos/GLGizmoMeasure.cpp
index 2eff5bb2ad..14caa193de 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoMeasure.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoMeasure.cpp
@@ -9,6 +9,7 @@
 
 #include "libslic3r/Model.hpp"
 #include "libslic3r/PresetBundle.hpp"
+#include "libslic3r/MeasureUtils.hpp"
 
 #include <imgui/imgui_internal.h>
 
@@ -1486,8 +1487,11 @@ void GLGizmoMeasure::on_render_input_window(float x, float y, float bottom_limit
             case Measure::SurfaceFeatureType::Circle:
             {
                 auto [center, radius, normal] = m_curr_feature->get_circle();
+                // generic point on circle, used to recalculate radius after transformation
+                const Vec3d on_circle = m_volume_matrix * (center + radius * Measure::get_orthogonal(normal, true));
                 center = m_volume_matrix * center;
-                normal = m_volume_matrix.matrix().block(0, 0, 3, 3).inverse().transpose() * normal;
+                normal = (m_volume_matrix.matrix().block(0, 0, 3, 3).inverse().transpose() * normal).normalized();
+                radius = (on_circle - center).norm();
                 if (use_inches) {
                     center = ObjectManipulation::mm_to_in * center;
                     radius = ObjectManipulation::mm_to_in * radius;