diff --git a/configure.ac b/configure.ac
index 8dded71..19ab3aa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -95,6 +95,9 @@ AM_CONDITIONAL([FREEBSD], [test -z "${host_os##freebsd*}"])
 AM_COND_IF([WIN32], [SP_LIBS='-lsetupapi'], [SP_LIBS=])
 AC_SUBST([SP_LIBS])
 
+AM_COND_IF([FREEBSD], [SP_PKGLIBS='libusb-2.0'], [SP_PKGLIBS=])
+AC_SUBST([SP_PKGLIBS])
+
 AM_COND_IF([MACOSX], [AC_CHECK_HEADER([IOKit/IOKitLib.h], [],
 	[AC_MSG_ERROR([IOKit/IOKitLib.h not found])])])
 
diff --git a/libserialport.pc.in b/libserialport.pc.in
index 1db208b..d945b2a 100644
--- a/libserialport.pc.in
+++ b/libserialport.pc.in
@@ -6,7 +6,7 @@ includedir=@includedir@
 Name: libserialport
 Description: Cross-platform serial port access library.
 URL: http://sigrok.org/wiki/Libserialport
-Requires.private:
+Requires.private: @SP_PKGLIBS@
 Version: @SP_PACKAGE_VERSION@
 Libs: -L${libdir} -lserialport
 Libs.private: @SP_LIBS@