diff --git a/configure.ac b/configure.ac
index ce17fef93157b7845fbcd88d4e109f370b47c8a1..3f32d8384e946b3b8f5d5864cf78b565e49f043a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -53,9 +53,9 @@ AC_DEFINE_UNQUOTED([OPUS_VERSION], ["$OPUS_VERSION"],
 
 # For libtool.
 dnl Please update these for releases.
-OPUS_LT_CURRENT=3
+OPUS_LT_CURRENT=4
 OPUS_LT_REVISION=0
-OPUS_LT_AGE=3
+OPUS_LT_AGE=4
 
 AC_SUBST(OPUS_LT_CURRENT)
 AC_SUBST(OPUS_LT_REVISION)