diff --git a/configure.ac b/configure.ac
index 2a15d720f9...186ab24978 100644
--- a/configure.ac
+++ b/configure.ac
@@ -254,7 +254,7 @@
     abi_strl=no
     abi_strmode=no
     abi_strnstr=no
-    abi_strtonum=no
+    abi_strtonum=yes
     abi_strtox=yes
     abi_timeconv=no
     # On libmd.