diff --git a/Makefile b/Makefile
index 5b986d7..56e74f8 100644
--- a/Makefile
+++ b/Makefile
@@ -16,6 +16,11 @@ define vault_env
 endef
 
 init:
+	@# Drop any stale dependency locks so provider sources are re-resolved
+	@# purely from config. Locks are gitignored and CI can reuse a workspace
+	@# carrying a lock from an earlier (old provider source) run, which -upgrade
+	@# on some OpenTofu versions tries to re-resolve instead of dropping.
+	@find . -name '.terraform.lock.hcl' -not -path '*/.git/*' -delete
 	@$(call vault_env) && \
 	terragrunt run --all --non-interactive init -- -upgrade