diff --git a/Makefile.am b/Makefile.am
index 44d7893..76d1723 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -80,7 +80,7 @@ include_HEADERS += $(lib_headers)
 lib_LTLIBRARIES += lib/libbluetooth.la
 
 lib_libbluetooth_la_SOURCES = $(lib_headers) $(lib_sources)
-lib_libbluetooth_la_LDFLAGS = $(AM_LDFLAGS) -version-info 21:3:18
+lib_libbluetooth_la_LDFLAGS = $(AM_LDFLAGS) -version-info 21:4:18
 lib_libbluetooth_la_DEPENDENCIES = $(local_headers)
 endif