diff --git a/docs/explanation/parts.rst b/docs/explanation/parts.rst
index 1c1d63a4c..b44de3cfa 100644
--- a/docs/explanation/parts.rst
+++ b/docs/explanation/parts.rst
@@ -36,24 +36,24 @@ data structures to describe them.
     graph LR
 
     subgraph Part
-    CRAFT_PART_SRC
-    CRAFT_PART_BUILD
-    CRAFT_PART_INSTALL
+    $CRAFT_PART_SRC
+    $CRAFT_PART_BUILD
+    $CRAFT_PART_INSTALL
     end
 
-    CRAFT_PROJECT_DIR
-    --->|pull| CRAFT_PART_SRC
-    --->|build| CRAFT_PART_BUILD
-    --->|build| CRAFT_PART_INSTALL
-    --->|stage| CRAFT_STAGE
-    --->|prime| CRAFT_PRIME
+    $CRAFT_PROJECT_DIR
+    --->|pull| $CRAFT_PART_SRC
+    --->|build| $CRAFT_PART_BUILD
+    --->|build| $CRAFT_PART_INSTALL
+    --->|stage| $CRAFT_STAGE
+    --->|prime| $CRAFT_PRIME
 
-    CRAFT_PROJECT_DIR
-    --->|overlay| CRAFT_OVERLAY
-    --->|stage| CRAFT_STAGE
+    $CRAFT_PROJECT_DIR
+    --->|overlay| $CRAFT_OVERLAY
+    --->|stage| $CRAFT_STAGE
 
-    CRAFT_PART_INSTALL
-    --->|organize| CRAFT_PART_INSTALL
+    $CRAFT_PART_INSTALL
+    --->|organize| $CRAFT_PART_INSTALL
 
 
 Describing a part