diff --git a/environment.mk b/environment.mk
index 0af083c..412dd46 100644
--- a/environment.mk
+++ b/environment.mk
@@ -15,7 +15,7 @@
 
 # Track file name of caller
 ifdef self
-  caller ::= self
+  caller ::= ${self}
 endif
 
 self ::= $(notdir $(lastword ${MAKEFILE_LIST}))