--- a/modules/zlib/src/moz.build
+++ b/modules/zlib/src/moz.build
@@ -11,16 +11,17 @@ EXPORTS += [
 ]
 
 if CONFIG['ZLIB_IN_MOZGLUE']:
     FINAL_LIBRARY = 'mozglue'
     DEFINES['IMPL_MFBT'] = True
 else:
     # The final library is in config/external/zlib
     FINAL_LIBRARY = 'zlib'
+    HostLibrary('hostzlib')
 
 SOURCES += [
     'adler32.c',
     'compress.c',
     'crc32.c',
     'deflate.c',
     'gzclose.c',
     'gzlib.c',
@@ -29,8 +30,11 @@ SOURCES += [
     'infback.c',
     'inffast.c',
     'inflate.c',
     'inftrees.c',
     'trees.c',
     'uncompr.c',
     'zutil.c',
 ]
+
+HOST_SOURCES = SOURCES
+