diff --git a/README.md b/README.md
index 410dba3..5d76fd7 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,12 @@ GNU Make, Bash and the usual POSIX utilities.
 
 `make USE_SYSTEM_NIM=1 test`
 
+## Make targets
+
+### show-deps
+
+Lists all Git submodule URLs, including nested ones.
+
 ## License
 
 Licensed and distributed under either of
diff --git a/makefiles/targets.mk b/makefiles/targets.mk
index 7708c88..a45826d 100644
--- a/makefiles/targets.mk
+++ b/makefiles/targets.mk
@@ -146,6 +146,12 @@ ctags:
 	--exclude=$(REPOS_DIR)/nim-bncurve/tests/tvectors.nim \
 	.
 
+# list all Git submodule URLs, including the nested ones
+show-deps:
+	{ git config --file .gitmodules --get-regexp url | cat ;\
+		git submodule foreach --quiet --recursive '[[ -f .gitmodules ]] && git config --file .gitmodules --get-regexp url | cat || true'; } \
+		| cut -d ' ' -f 2 | sort -u
+
 ############################
 # Windows-specific section #
 ############################