-lz in protobuf.pc belongs in Libs.private, not Libs
diff --git a/protobuf.pc.in b/protobuf.pc.in
index 8a53a43..29f2487 100644
--- a/protobuf.pc.in
+++ b/protobuf.pc.in
@@ -6,7 +6,8 @@
 Name: Protocol Buffers
 Description: Google's Data Interchange Format
 Version: @VERSION@
-Libs: -L${libdir} -lprotobuf @LIBS@ @PTHREAD_CFLAGS@ @PTHREAD_LIBS@
+Libs: -L${libdir} -lprotobuf @PTHREAD_CFLAGS@ @PTHREAD_LIBS@
+Libs.private: @LIBS@
 Cflags: -I${includedir} @PTHREAD_CFLAGS@
 # Commented out because it crashes pkg-config *sigh*:
 #   http://bugs.freedesktop.org/show_bug.cgi?id=13265