diff --git a/docs/Makefile b/docs/Makefile
index 6effe539..3b99b250 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -47,4 +47,6 @@ include $(OSMO_GSM_MANUALS_DIR)/build/Makefile.common.inc
 # Catch-all target: route all unknown targets to Sphinx using the new
 # "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
 %:
-	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+	@if [ "$@" != "shrink" ]; then \
+		$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O); \
+	fi