diff --git a/RepositoryExternal.mk b/RepositoryExternal.mk
index f93c819470e6..b3fbeba458d7 100644
--- a/RepositoryExternal.mk
+++ b/RepositoryExternal.mk
@@ -2665,6 +2665,8 @@ $(call gb_LinkTarget_add_libs,$(1),\
 
 endef
 
+gb_ExternalProject__use_png :=
+
 else # !SYSTEM_LIBPNG
 
 define gb_LinkTarget__use_png
@@ -2679,6 +2681,13 @@ $(call gb_LinkTarget__use_zlib,$(1))
 
 endef
 
+define gb_ExternalProject__use_png
+$(call gb_ExternalProject_use_static_libraries,$(1),\
+	png \
+)
+
+endef
+
 endif # !SYSTEM_LIBPNG
 
 
diff --git a/external/libzmf/ExternalProject_libzmf.mk b/external/libzmf/ExternalProject_libzmf.mk
index 87e669314413..da720fb14157 100644
--- a/external/libzmf/ExternalProject_libzmf.mk
+++ b/external/libzmf/ExternalProject_libzmf.mk
@@ -18,7 +18,9 @@ $(eval $(call gb_ExternalProject_register_targets,libzmf,\
 $(eval $(call gb_ExternalProject_use_externals,libzmf,\
 	boost_headers \
 	icu \
+	png \
 	revenge \
+	zlib \
 ))
 
 $(call gb_ExternalProject_get_state_target,libzmf,build) :