diff --git a/.murdock b/.murdock
index 5c7f147bea..982ff23e93 100755
--- a/.murdock
+++ b/.murdock
@@ -3,7 +3,7 @@
 # uncomment and change this to limit builds, e.g.,
 #export BOARDS="samr21-xpro native"
 # and / or
-#export APPS="examples/hello-world tests/unittests"
+export APPS="examples/hello-world tests/unittests tests/pkg_heatshrink"
 
 #
 : ${TEST_BOARDS_AVAILABLE:="esp32-wroom-32 samr21-xpro"}
diff --git a/pkg/pkg.mk b/pkg/pkg.mk
index abc67d51bf..70bbe9e196 100644
--- a/pkg/pkg.mk
+++ b/pkg/pkg.mk
@@ -115,7 +115,9 @@ $(PKG_PATCHED): $(PKG_PATCHED_PREREQUISITES)
 	$(call gen_dependency_files,$@.d,$(PKG_PATCHED_PREREQUISITES))
 	$(Q)$(GIT_IN_PKG) clean $(GIT_QUIET) -xdff '**' -e $(PKG_STATE:$(PKG_SOURCE_DIR)/%='%*')
 	$(Q)$(GIT_IN_PKG) checkout $(GIT_QUIET) -f $(PKG_VERSION)
-	$(Q)$(GIT_IN_PKG) $(GITFLAGS) am $(GITAMFLAGS) $(PKG_PATCHES) </dev/null
+	$(Q) if test -n "$(PKG_PATCHES)" ; then \
+	       $(GIT_IN_PKG) $(GITFLAGS) am $(GITAMFLAGS) $(PKG_PATCHES) </dev/null ; \
+	     fi
 	@touch $@
 
 $(PKG_DOWNLOADED): $(MAKEFILE_LIST) | $(PKG_SOURCE_DIR)/.git