diff --git a/distrho/DistrhoPlugin.hpp b/distrho/DistrhoPlugin.hpp
index 79f4c2df..64f3beab 100644
--- a/distrho/DistrhoPlugin.hpp
+++ b/distrho/DistrhoPlugin.hpp
@@ -69,34 +69,74 @@ struct ParameterRanges {
         max = 1.0f;
     }
 
+    /*!
+     * Fix default value within range.
+     */
+    void fixDefault() noexcept
+    {
+        fixValue(def);
+    }
+
+    /*!
+     * Fix a value within range.
+     */
     void fixValue(float& value) const noexcept
     {
-        if (value < min)
+        if (value <= min)
             value = min;
         else if (value > max)
             value = max;
     }
 
+    /*!
+     * Get a fixed value within range.
+     */
     float getFixedValue(const float& value) const noexcept
     {
-        if (value < min)
+        if (value <= min)
             return min;
-        else if (value > max)
+        if (value >= max)
             return max;
         return value;
     }
 
+    /*!
+     * Get a value normalized to 0.0<->1.0.
+     */
     float getNormalizedValue(const float& value) const noexcept
     {
-        const float newValue((value - min) / (max - min));
+        const float normValue((value - min) / (max - min));
 
-        if (newValue <= 0.0f)
+        if (normValue <= 0.0f)
             return 0.0f;
-        if (newValue >= 1.0f)
+        if (normValue >= 1.0f)
             return 1.0f;
-        return newValue;
+        return normValue;
     }
 
+    /*!
+     * Get a value normalized to 0.0<->1.0, fixed within range.
+     */
+    float getFixedAndNormalizedValue(const float& value) const noexcept
+    {
+        if (value <= min)
+            return 0.0f;
+        if (value >= max)
+            return 1.0f;
+
+        const float normValue((value - min) / (max - min));
+
+        if (normValue <= 0.0f)
+            return 0.0f;
+        if (normValue >= 1.0f)
+            return 1.0f;
+
+        return normValue;
+    }
+
+    /*!
+     * Get a proper value previously normalized to 0.0<->1.0.
+     */
     float getUnnormalizedValue(const float& value) const noexcept
     {
         return value * (max - min) + min;
@@ -113,7 +153,7 @@ struct Parameter {
     d_string unit;
     ParameterRanges ranges;
 
-    Parameter()
+    Parameter() noexcept
         : hints(0x0) {}
 
     void clear() noexcept
@@ -261,6 +301,8 @@ private:
     struct PrivateData;
     PrivateData* const pData;
     friend class PluginExporter;
+
+    DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(Plugin)
 };
 
 // -----------------------------------------------------------------------
diff --git a/distrho/DistrhoUI.hpp b/distrho/DistrhoUI.hpp
index bb8b334b..d61b67d5 100644
--- a/distrho/DistrhoUI.hpp
+++ b/distrho/DistrhoUI.hpp
@@ -87,6 +87,8 @@ private:
     struct PrivateData;
     PrivateData* const pData;
     friend class UIExporter;
+
+    DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(Plugin)
 };
 
 // -----------------------------------------------------------------------
diff --git a/distrho/DistrhoUtils.hpp b/distrho/DistrhoUtils.hpp
index 8dd5d511..46e3f258 100644
--- a/distrho/DistrhoUtils.hpp
+++ b/distrho/DistrhoUtils.hpp
@@ -163,6 +163,11 @@ void d_msleep(const uint msecs)
     } DISTRHO_SAFE_EXCEPTION("carla_msleep");
 }
 
+// -----------------------------------------------------------------------
+// we always need this class
+
+#include "extra/d_string.hpp"
+
 // -----------------------------------------------------------------------
 
 #endif // DISTRHO_UTILS_HPP_INCLUDED
diff --git a/distrho/extra/d_string.hpp b/distrho/extra/d_string.hpp
index 41b36fdc..3020d901 100644
--- a/distrho/extra/d_string.hpp
+++ b/distrho/extra/d_string.hpp
@@ -17,7 +17,7 @@
 #ifndef DISTRHO_STRING_HPP_INCLUDED
 #define DISTRHO_STRING_HPP_INCLUDED
 
-#include "../DistrhoUtils.hpp"
+#include "d_leakdetector.hpp"
 
 // -----------------------------------------------------------------------
 // d_string class
@@ -709,7 +709,7 @@ private:
         }
     }
 
-    //DISTRHO_LEAK_DETECTOR(d_string)
+    DISTRHO_LEAK_DETECTOR(d_string)
     DISTRHO_PREVENT_HEAP_ALLOCATION
 };