diff --git a/Makefile b/Makefile
index d00183e..f8d26d2 100644
--- a/Makefile
+++ b/Makefile
@@ -126,12 +126,26 @@
 endif
 
 ## Editor navigation files
-C_SOURCE_FILES = $(wildcard include/*/*.h library/*.[hc] programs/*/*.[hc] tests/suites/*.function)
+C_SOURCE_FILES = $(wildcard \
+	3rdparty/*/include/*/*.h 3rdparty/*/include/*/*/*.h 3rdparty/*/include/*/*/*/*.h \
+	3rdparty/*/*.c 3rdparty/*/*/*.c 3rdparty/*/*/*/*.c 3rdparty/*/*/*/*/*.c \
+	include/*/*.h \
+	library/*.[hc] \
+	programs/*/*.[hc] \
+	tests/include/*/*.h tests/include/*/*/*.h \
+	tests/src/*.c tests/src/*/*.c \
+	tests/suites/*.function \
+)
 # Exuberant-ctags invocation. Other ctags implementations may require different options.
 CTAGS = ctags --langmap=c:+.h.function -o
 tags: $(C_SOURCE_FILES)
 	$(CTAGS) $@ $(C_SOURCE_FILES)
 TAGS: $(C_SOURCE_FILES)
 	etags -o $@ $(C_SOURCE_FILES)
+global: GPATH GRTAGS GSYMS GTAGS
 GPATH GRTAGS GSYMS GTAGS: $(C_SOURCE_FILES)
 	ls $(C_SOURCE_FILES) | gtags -f - --gtagsconf .globalrc
+cscope: cscope.in.out cscope.po.out cscope.out
+cscope.in.out cscope.po.out cscope.out: $(C_SOURCE_FILES)
+	cscope -bq -u -Iinclude -Ilibrary $(patsubst %,-I%,$(wildcard 3rdparty/*/include)) -Itests/include $(C_SOURCE_FILES)
+.PHONY: cscope global