build: Update library version
diff --git a/Makefile.am b/Makefile.am
index 5510102..4ce642f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -80,7 +80,7 @@
 lib_LTLIBRARIES += lib/libbluetooth.la
 
 lib_libbluetooth_la_SOURCES = $(lib_headers) $(lib_sources)
-lib_libbluetooth_la_LDFLAGS = $(AM_LDFLAGS) -version-info 21:12:18
+lib_libbluetooth_la_LDFLAGS = $(AM_LDFLAGS) -version-info 21:13:18
 lib_libbluetooth_la_DEPENDENCIES = $(local_headers)
 endif