diff --git a/ext/pg_text_decoder.c b/ext/pg_text_decoder.c
index cc2d42d64..65c5c19f0 100644
--- a/ext/pg_text_decoder.c
+++ b/ext/pg_text_decoder.c
@@ -823,7 +823,7 @@ pg_text_dec_inet(t_pg_coder *conv, const char *val, int len, int tuple, int fiel
 	VALUE vmasks;
 	char dst[16];
 	char buf[64];
-	int af = strchr(val, '.') ? AF_INET : AF_INET6;
+	int af = strchr(val, ':') ? AF_INET6 : AF_INET;
 	int mask = -1;
 
 	if (len >= 64) {
diff --git a/spec/pg/basic_type_map_for_results_spec.rb b/spec/pg/basic_type_map_for_results_spec.rb
index 99d19c48c..2b7bed82a 100644
--- a/spec/pg/basic_type_map_for_results_spec.rb
+++ b/spec/pg/basic_type_map_for_results_spec.rb
@@ -351,6 +351,9 @@
 						'1234:3456:5678:789a:9abc:bced:edf0:f012/32',
 						'1234:3456:5678:789a:9abc:bced:edf0:f012/64',
 						'1234:3456:5678:789a:9abc:bced:edf0:f012/96',
+						'::ffff:1.2.3.4',
+						'::ffff:1.2.3.4/120',
+						'::1.2.3.4',
 					]
 					sql_vals = vals.map{|v| "CAST('#{v}' AS inet)"}
 					res = @conn.exec_params(("SELECT " + sql_vals.join(', ')), [], format )
@@ -374,6 +377,7 @@
 						'1234:3456:5678:789a::/64',
 						'1234:3456:5678:789a:9abc:bced::/96',
 						'1234:3456:5678:789a:9abc:bced:edf0:f012/128',
+						'::ffff:1.2.3.0/120',
 					]
 					sql_vals = vals.map { |v| "CAST('#{v}' AS cidr)" }
 					res = @conn.exec_params(("SELECT " + sql_vals.join(', ')), [], format )