diff --git a/pkg.c b/pkg.c
index 4e4d464..2ce3605 100644
--- a/pkg.c
+++ b/pkg.c
@@ -32,17 +32,19 @@ pkg_get_pkgconfig_path(void)
 	static bool computed = false;
 	static char path[PKG_CONFIG_PATH_SZ];
 	char *env_path;
+	size_t len;
 
 	if (computed)
 		return path;
 
 	strncpy(path, PKG_DEFAULT_PATH, sizeof path);
+	len = strlen(PKG_DEFAULT_PATH);
 
 	env_path = getenv("PKG_CONFIG_PATH");
 	if (env_path != NULL)
 	{
-		strncat(path, ":", sizeof path);
-		strncat(path, env_path, sizeof path);
+		strncat(path, ":", sizeof path - len - 1);
+		strncat(path, env_path, sizeof path - len - 2);
 	}
 
 	return path;