diff --git a/Handbook/GNUmakefile b/Handbook/GNUmakefile
index 6dc8970a..59754f1e 100644
--- a/Handbook/GNUmakefile
+++ b/Handbook/GNUmakefile
@@ -182,14 +182,14 @@ else # ($(SG_BUILD_PLATFORM),$(SG_BUILD_PLATFORM_LINUX))
 $(error The target operating system is not supported!)
 endif # ($(SG_BUILD_PLATFORM),$(SG_BUILD_PLATFORM_LINUX))
 
-SG_DIST_DIR						:=	$(SG_HANDBOOK_DIR)/dist
 ifeq ($(SG_BUILD_PLATFORM),$(SG_BUILD_PLATFORM_LINUX))
-SG_PYTHON_VENV_DIR		:=	$(shell mktemp -d)/sg-ue-handbook-venv
-SG_PYTHON_VENV_BIN_DIR	:=	$(SG_PYTHON_VENV_DIR)/bin
-export PATH			:=	$(SG_GENTOO_PY_VENV_BIN_DIR):$(PATH)
-export PWD			:=	$(SG_GENTOO_PY_VENV_BIN_DIR)
-export VIRTUAL_ENV	:=	$(SG_GENTOO_PY_VENV_DIR)
+SG_LINUX_PYTHON_VENV_DIR		:=	$(shell mktemp -d)/sg-ue-handbook-venv
+SG_LINUX_PYTHON_VENV_BIN_DIR	:=	$(SG_LINUX_PYTHON_VENV_DIR)/bin
+export PATH			:=	$(SG_LINUX_PYTHON_VENV_BIN_DIR):$(PATH)
+export PWD			:=	$(SG_LINUX_PYTHON_VENV_BIN_DIR)
+export VIRTUAL_ENV	:=	$(SG_LINUX_PYTHON_VENV_DIR)
 else ifeq ($(SG_BUILD_PLATFORM),$(SG_BUILD_PLATFORM_WINDOWS))
+SG_DIST_DIR						:=	$(SG_HANDBOOK_DIR)/dist
 SG_WINPYTHON_DIR				:=	$(SG_DIST_DIR)/winpython
 SG_WINPYTHON_BIN_DIR			:=	$(SG_WINPYTHON_DIR)//python-3.12.4.amd64
 SG_WINPYTHON_BIN_SCRIPTS_DIR	:=	$(SG_WINPYTHON_BIN_DIR)/Scripts
@@ -257,6 +257,12 @@ install-build-deps:
 	@cargo install xq --locked
 	@cargo install mdbook-alerts --locked
 	@cargo install mdbook-pdf --locked
+ifeq ($(SG_BUILD_PLATFORM),$(SG_BUILD_PLATFORM_LINUX))
+	@echo "Installing mdbook-pdf-outline..."
+	@python -m venv $(VIRTUAL_ENV) && \
+		source $(SG_LINUX_PYTHON_VENV_BIN_DIR)/activate && \
+		pip install mdbook-pdf-outline 2>/dev/null
+endif # ($(SG_BUILD_PLATFORM),$(SG_BUILD_PLATFORM_LINUX))
 
 ################################################################################
 # Make Targets - mdBook