diff --git a/src/Makefile b/src/Makefile
index bd83c05..3d3aadb 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -47,7 +47,7 @@ LIBRARY = nt
 nt_LIBS += pvData Com
 
 # shared library ABI version.
-SHRLIB_VERSION ?= 5.2.2
+SHRLIB_VERSION ?= 6.0.0
 
 include $(TOP)/configure/RULES