diff --git a/src/builtin_status.cpp b/src/builtin_status.cpp
index 4862a8897..a7544ab1a 100644
--- a/src/builtin_status.cpp
+++ b/src/builtin_status.cpp
@@ -429,7 +429,7 @@ int builtin_status(parser_t &parser, io_streams_t &streams, wchar_t **argv) {
                 streams.out.append(var->as_string());
                 streams.out.push_back(L'\n');
             } else {
-                streams.out.append(program_name);
+                streams.out.append(str2wcstring(program_name).c_str());
                 streams.out.push_back(L'\n');
             }
             break;
diff --git a/src/builtin_test.cpp b/src/builtin_test.cpp
index 07ae926b9..0752d73b2 100644
--- a/src/builtin_test.cpp
+++ b/src/builtin_test.cpp
@@ -554,7 +554,7 @@ unique_ptr<expression> test_parser::parse_args(const wcstring_list_t &args, wcst
         assert(result->range.end <= args.size());
         if (result->range.end < args.size()) {
             if (err.empty()) {
-                append_format(err, L"%ls: unexpected argument at index %lu: '%ls'\n", program_name,
+                append_format(err, L"%s: unexpected argument at index %lu: '%ls'\n", program_name,
                               (unsigned long)result->range.end, args.at(result->range.end).c_str());
             }
             result.reset(NULL);
diff --git a/src/common.cpp b/src/common.cpp
index 82c85181f..e1b7e4282 100644
--- a/src/common.cpp
+++ b/src/common.cpp
@@ -62,7 +62,7 @@ const wchar_t *ellipsis_str = nullptr;
 wchar_t omitted_newline_char;
 wchar_t obfuscation_read_char;
 bool g_profiling_active = false;
-const wchar_t *program_name;
+const char *program_name;
 int debug_level = 1;         // default maximum debug output level (errors and warnings)
 int debug_stack_frames = 0;  // default number of stack frames to show on debug() calls
 
@@ -603,16 +603,16 @@ ssize_t read_loop(int fd, void *buff, size_t count) {
 /// like `debug()`. It is only intended to supress diagnostic noise from testing things like the
 /// fish parser where we expect a lot of diagnostic messages due to testing error conditions.
 bool should_suppress_stderr_for_tests() {
-    return program_name && !wcscmp(program_name, TESTS_PROGRAM_NAME);
+    return program_name && !strcmp(program_name, TESTS_PROGRAM_NAME);
 }
 
 static void debug_shared(const wchar_t level, const wcstring &msg) {
     pid_t current_pid = getpid();
 
     if (current_pid == initial_pid) {
-        fwprintf(stderr, L"<%lc> %ls: %ls\n", (unsigned long)level, program_name, msg.c_str());
+        fwprintf(stderr, L"<%lc> %s: %ls\n", (unsigned long)level, program_name, msg.c_str());
     } else {
-        fwprintf(stderr, L"<%lc> %ls: %d: %ls\n", (unsigned long)level, program_name, current_pid,
+        fwprintf(stderr, L"<%lc> %s: %d: %ls\n", (unsigned long)level, program_name, current_pid,
                  msg.c_str());
     }
 }
diff --git a/src/common.h b/src/common.h
index 83d6cd0ba..862256c9c 100644
--- a/src/common.h
+++ b/src/common.h
@@ -221,7 +221,7 @@ extern int debug_stack_frames;
 extern bool g_profiling_active;
 
 /// Name of the current program. Should be set at startup. Used by the debug function.
-extern const wchar_t *program_name;
+extern const char *program_name;
 
 /// Set to false if it's been determined we can't trust the last modified timestamp on the tty.
 extern const bool has_working_tty_timestamps;
@@ -532,7 +532,7 @@ string_fuzzy_match_t string_fuzzy_match_string(const wcstring &string,
                                                fuzzy_match_type_t limit_type = fuzzy_match_none);
 
 // Check if we are running in the test mode, where we should suppress error output
-#define TESTS_PROGRAM_NAME L"(ignore)"
+#define TESTS_PROGRAM_NAME "(ignore)"
 bool should_suppress_stderr_for_tests();
 
 void assert_is_main_thread(const char *who);
diff --git a/src/env_universal_common.cpp b/src/env_universal_common.cpp
index 7fd8bf1e9..ac05ff382 100644
--- a/src/env_universal_common.cpp
+++ b/src/env_universal_common.cpp
@@ -1047,7 +1047,7 @@ class universal_notifier_shmem_poller_t : public universal_notifier_t {
 
         // Use a path based on our uid to avoid collisions.
         char path[NAME_MAX];
-        snprintf(path, sizeof path, "/%ls_shmem_%d", program_name ? program_name : L"fish",
+        snprintf(path, sizeof path, "/%s_shmem_%d", L"fish",
                  getuid());
 
         bool errored = false;
@@ -1181,8 +1181,7 @@ class universal_notifier_notifyd_t : public universal_notifier_t {
     void setup_notifyd() {
         // Per notify(3), the user.uid.%d style is only accessible to processes with that uid.
         char local_name[256];
-        snprintf(local_name, sizeof local_name, "user.uid.%d.%ls.uvars", getuid(),
-                 program_name ? program_name : L"fish");
+        snprintf(local_name, sizeof local_name, "user.uid.%d.fish.uvars", getuid());
         name.assign(local_name);
 
         uint32_t status =
diff --git a/src/fish.cpp b/src/fish.cpp
index 49110ac1e..70c0661c5 100644
--- a/src/fish.cpp
+++ b/src/fish.cpp
@@ -100,7 +100,7 @@ static struct config_paths_t determine_config_directory_paths(const char *argv0)
 #ifdef CMAKE_BINARY_DIR
         // Detect if we're running right out of the CMAKE build directory
         if (string_prefixes_string(CMAKE_BINARY_DIR, exec_path.c_str())) {
-            debug(2, "Running out of build directory, using paths relative to CMAKE_SOURCE_DIR:\n %s", CMAKE_SOURCE_DIR);
+            debug(2, "Running out of5 build directory, using paths relative to CMAKE_SOURCE_DIR:\n %s", CMAKE_SOURCE_DIR);
 
             done = true;
             paths.data = wcstring{L"" CMAKE_SOURCE_DIR} + L"/share";
@@ -334,7 +334,13 @@ int main(int argc, char **argv) {
     int res = 1;
     int my_optind = 0;
 
-    program_name = L"fish";
+    const char *dummy_argv[2] = {"fish", NULL};
+    if (!argv[0]) {
+        argv = (char **)dummy_argv;  //!OCLINT(parameter reassignment)
+        argc = 1;                    //!OCLINT(parameter reassignment)
+    }
+
+    program_name = argv[0];
     set_main_thread();
     setup_fork_guards();
     signal_unblock_all();
@@ -344,11 +350,6 @@ int main(int argc, char **argv) {
     // struct stat tmp;
     // stat("----------FISH_HIT_MAIN----------", &tmp);
 
-    const char *dummy_argv[2] = {"fish", NULL};
-    if (!argv[0]) {
-        argv = (char **)dummy_argv;  //!OCLINT(parameter reassignment)
-        argc = 1;                    //!OCLINT(parameter reassignment)
-    }
     fish_cmd_opts_t opts;
     my_optind = fish_parse_opt(argc, argv, &opts);
 
diff --git a/src/fish_indent.cpp b/src/fish_indent.cpp
index 59e560bd5..f16cc0a45 100644
--- a/src/fish_indent.cpp
+++ b/src/fish_indent.cpp
@@ -381,7 +381,7 @@ static std::string html_colorize(const wcstring &text,
 static std::string no_colorize(const wcstring &text) { return wcs2string(text); }
 
 int main(int argc, char *argv[]) {
-    program_name = L"fish_indent";
+    program_name = argv[0];
     set_main_thread();
     setup_fork_guards();
     // Using the user's default locale could be a problem if it doesn't use UTF-8 encoding. That's
diff --git a/src/fish_key_reader.cpp b/src/fish_key_reader.cpp
index aec1626be..8d3eba92e 100644
--- a/src/fish_key_reader.cpp
+++ b/src/fish_key_reader.cpp
@@ -383,7 +383,7 @@ static bool parse_flags(int argc, char **argv, bool *continuous_mode) {
 }
 
 int main(int argc, char **argv) {
-    program_name = L"fish_key_reader";
+    program_name = argv[0];
     bool continuous_mode = false;
 
     if (!parse_flags(argc, argv, &continuous_mode)) return 1;
diff --git a/src/parser.cpp b/src/parser.cpp
index b16c86e47..ea53bd6b4 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -775,7 +775,7 @@ void parser_t::get_backtrace(const wcstring &src, const parse_error_list_t &erro
                 prefix = format_string(_(L"%ls: "), user_presentable_path(filename).c_str());
             }
         } else {
-            prefix = L"fish: ";
+            prefix = format_string(L"%s: ", program_name);
         }
 
         const wcstring description =
diff --git a/src/proc.cpp b/src/proc.cpp
index 5e0523187..7a1bcf6b7 100644
--- a/src/proc.cpp
+++ b/src/proc.cpp
@@ -659,7 +659,7 @@ static int process_clean_after_marking(bool allow_interactive) {
                     // we don't need to.
                     const wcstring job_number_desc =
                         (job_count == 1) ? wcstring() : format_string(_(L"Job %d, "), j->job_id);
-                    fwprintf(stdout, _(L"%ls: %ls\'%ls\' terminated by signal %ls (%ls)"),
+                    fwprintf(stdout, _(L"%s: %ls\'%ls\' terminated by signal %ls (%ls)"),
                              program_name, job_number_desc.c_str(),
                              truncate_command(j->command()).c_str(), sig2wcs(WTERMSIG(p->status)),
                              signal_get_desc(WTERMSIG(p->status)));
@@ -667,7 +667,7 @@ static int process_clean_after_marking(bool allow_interactive) {
                     const wcstring job_number_desc =
                         (job_count == 1) ? wcstring() : format_string(L"from job %d, ", j->job_id);
                     const wchar_t *fmt =
-                        _(L"%ls: Process %d, \'%ls\' %ls\'%ls\' terminated by signal %ls (%ls)");
+                        _(L"%s: Process %d, \'%ls\' %ls\'%ls\' terminated by signal %ls (%ls)");
                     fwprintf(stdout, fmt, program_name, p->pid, p->argv0(), job_number_desc.c_str(),
                              truncate_command(j->command()).c_str(), sig2wcs(WTERMSIG(p->status)),
                              signal_get_desc(WTERMSIG(p->status)));
diff --git a/src/reader.cpp b/src/reader.cpp
index 70b6c4a3d..c0a7e89fc 100644
--- a/src/reader.cpp
+++ b/src/reader.cpp
@@ -2037,7 +2037,7 @@ void reader_run_command(parser_t &parser, const wcstring &cmd) {
     term_steal();
 
     // For compatibility with fish 2.0's $_, now replaced with `status current-command`
-    env_set_one(L"_", ENV_GLOBAL, program_name);
+    env_set_one(L"_", ENV_GLOBAL, str2wcstring(program_name).c_str());
 
 #ifdef HAVE__PROC_SELF_STAT
     proc_update_jiffies();