diff --git a/src/lib/log/log.c b/src/lib/log/log.c
index ddd0eac6e7..dc53b386b0 100644
--- a/src/lib/log/log.c
+++ b/src/lib/log/log.c
@@ -276,8 +276,8 @@ static int log_time_granularity = 1;
 
 /** Define log time granularity for all logs to be <b>granularity_msec</b>
  * milliseconds. */
-void
-set_log_time_granularity(int granularity_msec)
+MOCK_IMPL(void,
+set_log_time_granularity,(int granularity_msec))
 {
   log_time_granularity = granularity_msec;
   tor_log_sigsafe_err_set_granularity(granularity_msec);
@@ -937,9 +937,9 @@ set_log_severity_config(int loglevelMin, int loglevelMax,
 
 /** Add a log handler named <b>name</b> to send all messages in <b>severity</b>
  * to <b>fd</b>. Copies <b>severity</b>. Helper: does no locking. */
-static void
-add_stream_log_impl(const log_severity_list_t *severity,
-                    const char *name, int fd)
+MOCK_IMPL(STATIC void,
+add_stream_log_impl,(const log_severity_list_t *severity,
+                     const char *name, int fd))
 {
   logfile_t *lf;
   lf = tor_malloc_zero(sizeof(logfile_t));
@@ -1199,10 +1199,10 @@ mark_logs_temp(void)
  * opening the logfile failed, -1 is returned and errno is set appropriately
  * (by open(2)).  Takes ownership of fd.
  */
-int
-add_file_log(const log_severity_list_t *severity,
-             const char *filename,
-             int fd)
+MOCK_IMPL(int,
+add_file_log,(const log_severity_list_t *severity,
+              const char *filename,
+              int fd))
 {
   logfile_t *lf;
 
diff --git a/src/lib/log/log.h b/src/lib/log/log.h
index 4dead0fd2c..374db76e12 100644
--- a/src/lib/log/log.h
+++ b/src/lib/log/log.h
@@ -163,11 +163,11 @@ int parse_log_severity_config(const char **cfg,
                               log_severity_list_t *severity_out);
 void set_log_severity_config(int minSeverity, int maxSeverity,
                              log_severity_list_t *severity_out);
-void add_stream_log(const log_severity_list_t *severity, const char *name,
-                    int fd);
-int add_file_log(const log_severity_list_t *severity,
-                 const char *filename,
-                 int fd);
+void add_stream_log(const log_severity_list_t *severity,
+                    const char *name, int fd);
+MOCK_DECL(int, add_file_log,(const log_severity_list_t *severity,
+                             const char *filename,
+                             int fd));
 
 #ifdef HAVE_SYSLOG_H
 int add_syslog_log(const log_severity_list_t *severity,
@@ -194,7 +194,7 @@ void change_callback_log_severity(int loglevelMin, int loglevelMax,
 void flush_pending_log_callbacks(void);
 void flush_log_messages_from_startup(void);
 void log_set_application_name(const char *name);
-void set_log_time_granularity(int granularity_msec);
+MOCK_DECL(void, set_log_time_granularity,(int granularity_msec));
 void truncate_logs(void);
 
 void tor_log(int severity, log_domain_mask_t domain, const char *format, ...)
@@ -306,6 +306,8 @@ extern const log_domain_mask_t LD_GENERAL_;
 MOCK_DECL(STATIC void, logv, (int severity, log_domain_mask_t domain,
     const char *funcname, const char *suffix, const char *format,
     va_list ap) CHECK_PRINTF(5,0));
+MOCK_DECL(STATIC void, add_stream_log_impl,(
+         const log_severity_list_t *severity, const char *name, int fd));
 #endif
 
 #if defined(LOG_PRIVATE) || defined(TOR_UNIT_TESTS)