diff --git a/src/zabbix_server/trapper/nodecommand.c b/src/zabbix_server/trapper/nodecommand.c
index 739b479d..ffa6eeab 100644
--- a/src/zabbix_server/trapper/nodecommand.c
+++ b/src/zabbix_server/trapper/nodecommand.c
@@ -498,9 +498,12 @@ static int	execute_script(zbx_uint64_t scriptid, zbx_uint64_t hostid, zbx_uint64
 			goto fail;
 		}
 
+		zabbix_log(LOG_LEVEL_DEBUG, "Substituting macros in script command: '%s'", script.command);
 		substitute_macro(script.command, "{MANUALINPUT}", manualinput, &expanded_cmd, &expanded_cmd_size);
+		zabbix_log(LOG_LEVEL_DEBUG, "Macros substituted: original script body: (%p) '%s', final script body: (%p) '%s'", script.command, script.command, expanded_cmd, expanded_cmd);
 
 		script.command = zbx_strdup(script.command, expanded_cmd);
+		zabbix_log(LOG_LEVEL_DEBUG, "Script command replaced: (%p) '%s'", script.command, script.command);
 
 		zbx_free(expanded_cmd);
 	}
@@ -524,6 +527,7 @@ static int	execute_script(zbx_uint64_t scriptid, zbx_uint64_t hostid, zbx_uint64
 				NULL, &host, NULL, NULL, NULL, NULL, NULL, user_timezone, &script.command, macro_type,
 				error, sizeof(error)))
 		{
+			zabbix_log(LOG_LEVEL_DEBUG, "Simple, unmasked, macro substitution failed");
 			goto fail;
 		}
 
@@ -531,6 +535,7 @@ static int	execute_script(zbx_uint64_t scriptid, zbx_uint64_t hostid, zbx_uint64
 				NULL, NULL, NULL, NULL, NULL, user_timezone, &script.command_orig, macro_type, error,
 				sizeof(error)))
 		{
+			zabbix_log(LOG_LEVEL_DEBUG, "Simple macro substitution failed");
 			THIS_SHOULD_NEVER_HAPPEN;
 			goto fail;
 		}