Fix typo.
diff --git a/cmake-config.h.in b/cmake-config.h.in
index 3067607..60c2dae 100644
--- a/cmake-config.h.in
+++ b/cmake-config.h.in
@@ -24,7 +24,7 @@
 typedef long ssize_t
 #  elif SIZE_T_LIBZIP == LONG_LONG_LIBZIP
 typedef long long ssize_t
-#  elif
+#  else
 #error no suitable type for ssize_t found
 #  endif
 #endif