diff --git a/chapters/install/packaging.md b/chapters/install/packaging.md
index 9e3005a..59596a6 100644
--- a/chapters/install/packaging.md
+++ b/chapters/install/packaging.md
@@ -15,7 +15,7 @@ set(CPACK_RESOURCE_FILE_README "${CMAKE_CURRENT_SOURCE_DIR}/README.md")
 
 These are the most common variables you'll need to make a binary package. A binary package uses the install mechanism of CMake, so anything that is installed will be present.
 
-You can also make a source package. You should set `CMAKE_SOURCE_IGNORE_FILES` to regular expressions that ensure you don't pick up any extra files (like the build directory or git details); otherwise `make package_source` will bundle up literally everything in the source directory. You can also set the source generator to make your favorite types of files for source packages:
+You can also make a source package. You should set `CPACK_SOURCE_IGNORE_FILES` to regular expressions that ensure you don't pick up any extra files (like the build directory or git details); otherwise `make package_source` will bundle up literally everything in the source directory. You can also set the source generator to make your favorite types of files for source packages:
 
 ```cmake
 set(CPACK_SOURCE_GENERATOR "TGZ;ZIP")