diff --git a/source/blender/blenkernel/intern/curves_geometry.cc b/source/blender/blenkernel/intern/curves_geometry.cc
index 0fd58a52f81..21b1fbffa02 100644
--- a/source/blender/blenkernel/intern/curves_geometry.cc
+++ b/source/blender/blenkernel/intern/curves_geometry.cc
@@ -797,6 +797,13 @@ Span<float3> CurvesGeometry::evaluated_normals() const
             break;
         }
 
+#ifdef DEBUG
+        for (const int i : evaluated_points) {
+          const float3 &normal = evaluated_normals[i];
+          BLI_ASSERT_UNIT_V3(normal);
+        }
+#endif
+
         /* If the "tilt" attribute exists, rotate the normals around the tangents by the
          * evaluated angles. We can avoid copying the tilts to evaluate them for poly curves. */
         if (!(tilt.is_single() && tilt.get_internal_single() == 0.0f)) {
@@ -817,6 +824,13 @@ Span<float3> CurvesGeometry::evaluated_normals() const
                                           evaluated_tilts.as_span());
           }
         }
+
+#ifdef DEBUG
+        for (const int i : evaluated_points) {
+          const float3 &normal = evaluated_normals[i];
+          BLI_ASSERT_UNIT_V3(normal);
+        }
+#endif
       }
     });
   });