diff --git a/intern/cycles/blender/addon/properties.py b/intern/cycles/blender/addon/properties.py
index 64541b86a9e..a86f162ae5f 100644
--- a/intern/cycles/blender/addon/properties.py
+++ b/intern/cycles/blender/addon/properties.py
@@ -116,7 +116,7 @@ enum_volume_sampling = (
 
 enum_volume_interpolation = (
     ('LINEAR', "Linear", "Good smoothness and speed"),
-    ('CUBIC', 'Cubic', 'Smoothed high quality interpolation, but slower')
+    ('CUBIC', "Cubic", "Smoothed high quality interpolation, but slower")
     )
 
 
@@ -652,7 +652,7 @@ class CyclesMaterialSettings(bpy.types.PropertyGroup):
 
         cls.volume_interpolation = EnumProperty(
                 name="Volume Interpolation",
-                description="Interpolation method to use for volumes",
+                description="Interpolation method to use for smoke/fire volumes",
                 items=enum_volume_interpolation,
                 default='LINEAR',
                 )
diff --git a/intern/cycles/render/graph.cpp b/intern/cycles/render/graph.cpp
index 6d05e5249cb..9896eaba89b 100644
--- a/intern/cycles/render/graph.cpp
+++ b/intern/cycles/render/graph.cpp
@@ -509,7 +509,7 @@ void ShaderGraph::break_cycles(ShaderNode *node, vector<bool>& visited, vector<b
 
 void ShaderGraph::clean()
 {
-	/* remove proxy and unnecessary mix nodes */
+	/* remove proxy and unnecessary nodes */
 	remove_unneeded_nodes();
 
 	/* we do two things here: find cycles and break them, and remove unused