diff --git a/include/criterion/logging.h b/include/criterion/logging.h
index 450023b..76fc6ea 100644
--- a/include/criterion/logging.h
+++ b/include/criterion/logging.h
@@ -120,13 +120,9 @@ struct criterion_output_provider {
 };
 
 extern struct criterion_output_provider normal_logging;
-extern struct criterion_output_provider tap_logging;
-extern struct criterion_output_provider xml_logging;
 
 CR_END_C_API
 
 #define CR_NORMAL_LOGGING (&normal_logging)
-#define CR_TAP_LOGGING    (&tap_logging)
-#define CR_XML_LOGGING    (&xml_logging)
 
 #endif /* !CRITERION_LOGGING_H_ */
diff --git a/src/entry/main.c b/src/entry/main.c
index 007b320..f711c8b 100644
--- a/src/entry/main.c
+++ b/src/entry/main.c
@@ -187,9 +187,6 @@ int criterion_handle_args(int argc, char *argv[], bool handle_unknown_arg) {
         opt->pattern = env_pattern;
 #endif
 
-    bool use_tap = !strcmp("1", DEF(getenv("CRITERION_ENABLE_TAP"), "0"));
-    bool use_xml = !strcmp("1", DEF(getenv("CRITERION_ENABLE_XML"), "0"));
-
     opt->measure_time = !!strcmp("1", DEF(getenv("CRITERION_DISABLE_TIME_MEASUREMENTS"), "0"));
 
     bool do_list_tests = false;
@@ -207,8 +204,6 @@ int criterion_handle_args(int argc, char *argv[], bool handle_unknown_arg) {
 #ifdef HAVE_PCRE
             case 'p': criterion_options.pattern           = optarg; break;
 #endif
-            case 't': use_tap = true; break;
-            case 'x': use_xml = true; break;
             case 'l': do_list_tests = true; break;
             case 'v': do_print_version = true; break;
             case 'h': do_print_usage = true; break;
@@ -216,10 +211,6 @@ int criterion_handle_args(int argc, char *argv[], bool handle_unknown_arg) {
             default : do_print_usage = handle_unknown_arg; break;
         }
     }
-    if (use_tap)
-        criterion_options.output_provider = CR_TAP_LOGGING;
-    else if (use_xml)
-        criterion_options.output_provider = CR_XML_LOGGING;
     if (do_print_usage)
         return print_usage(argv[0]);
     if (do_print_version)