diff --git a/range.cpp b/range.cpp
index 240af69d..f0c74195 100644
--- a/range.cpp
+++ b/range.cpp
@@ -107,7 +107,6 @@ range<T>::expand (T val) {
 template <typename T>
 double
 range<T>::normalise (T val) const {
-    CHECK_SOFT (val >= min && val <= max);
     return ((double)val - min) /
            ((double)max - min);
 }
diff --git a/range.hpp b/range.hpp
index 396a2dc0..e1ab4169 100644
--- a/range.hpp
+++ b/range.hpp
@@ -49,7 +49,9 @@ namespace util {
         /// Expand the range to include this value if necessary
         void expand (T val);
 
-        /// Normalise a number to [0, 1] within the range. Does not check bounds.
+        /// Normalise a number to [0, 1] within the range. Does not check
+        /// bounds, it is the caller's responsibility to clamp the result if
+        /// needed.
         double normalise (T val) const;
 
         range& operator*= (T);