diff --git a/Documentation/Makefile.sphinx b/Documentation/Makefile.sphinx
index 02d84e6dc7fc..e14d82a98062 100644
--- a/Documentation/Makefile.sphinx
+++ b/Documentation/Makefile.sphinx
@@ -66,10 +66,10 @@ quiet_cmd_sphinx = SPHINX  $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
 	$(abspath $(BUILDDIR)/$3/$4)
 
 htmldocs:
-	@$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,html,$(var),,$(var)))
+	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,html,$(var),,$(var)))
 
 latexdocs:
-	@$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,latex,$(var),latex,$(var)))
+	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,latex,$(var),latex,$(var)))
 
 ifeq ($(HAVE_PDFLATEX),0)
 
@@ -85,10 +85,10 @@ pdfdocs: latexdocs
 endif # HAVE_PDFLATEX
 
 epubdocs:
-	@$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,epub,$(var),epub,$(var)))
+	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,epub,$(var),epub,$(var)))
 
 xmldocs:
-	@$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,xml,$(var),xml,$(var)))
+	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,xml,$(var),xml,$(var)))
 
 # no-ops for the Sphinx toolchain
 sgmldocs: