--- a/libh2o-evloop.pc.in
+++ b/libh2o-evloop.pc.in
@@ -7,5 +7,5 @@
 Description: An optimized HTTP/1.x & HTTP/2 library
 URL: https://h2o.examp1e.net/
 Version: @LIBRARY_VERSION_MAJOR@.@LIBRARY_VERSION_MINOR@.@LIBRARY_VERSION_PATCH@
-Libs: -L${libdir} -lh2o-evloop
+Libs: -L${libdir} -lh2o-evloop -lwslay
 Cflags: -I${includedir}