diff --git a/src/afterfact.rs b/src/afterfact.rs
index 5f7dff25..9d83f8c2 100644
--- a/src/afterfact.rs
+++ b/src/afterfact.rs
@@ -228,7 +228,8 @@ fn emit_csv<W: std::io::Write>(
     let mut timestamps: Vec<i64> = Vec::new();
     let mut plus_header = true;
     let mut detected_record_idset: HashSet<String> = HashSet::new();
-    for (time, detect_infos) in messages.iter() {
+    let detect_union = messages.iter();
+    for (time, detect_infos) in detect_union {
         timestamps.push(_get_timestamp(time));
         for detect_info in detect_infos {
             detected_record_idset.insert(format!("{}_{}", time, detect_info.eventid));
@@ -429,7 +430,7 @@ fn _get_serialized_disp_output(dispformat: Option<DisplayFormat>) -> String {
 
 /// return str position in output file
 fn _format_cellpos(colval: &str, column: ColPos) -> String {
-    return match column {
+    match column {
         ColPos::First => format!("{} ", colval),
         ColPos::Last => format!(" {}", colval),
         ColPos::Other => format!(" {} ", colval),
diff --git a/src/detections/pivot.rs b/src/detections/pivot.rs
index f8be1801..24f6ad69 100644
--- a/src/detections/pivot.rs
+++ b/src/detections/pivot.rs
@@ -57,8 +57,8 @@ pub fn insert_pivot_keyword(event_record: &Value) {
     } else {
         return;
     }
-
-    for (_, pivot) in PIVOT_KEYWORD.write().unwrap().iter_mut() {
+    let mut pivots = PIVOT_KEYWORD.write().unwrap().iter_mut();
+    for (_, pivot) in pivots {
         for field in &pivot.fields {
             if let Some(array_str) = configs::EVENTKEY_ALIAS.get_event_key(&String::from(field)) {
                 let split: Vec<&str> = array_str.split('.').collect();
diff --git a/src/detections/print.rs b/src/detections/print.rs
index 6d4433f3..c7288369 100644
--- a/src/detections/print.rs
+++ b/src/detections/print.rs
@@ -252,7 +252,8 @@ impl AlertMessage {
                 .as_bytes(),
             )
             .ok();
-        for error_log in ERROR_LOG_STACK.lock().unwrap().iter() {
+        let error_logs = ERROR_LOG_STACK.lock().unwrap().iter();
+        for error_log in error_logs {
             writeln!(error_log_writer, "{}", error_log).ok();
         }
         println!(
diff --git a/src/detections/rule/matchers.rs b/src/detections/rule/matchers.rs
index 744b45a0..5ed1a8c8 100644
--- a/src/detections/rule/matchers.rs
+++ b/src/detections/rule/matchers.rs
@@ -483,7 +483,7 @@ impl PipeElement {
                     wildcard_regex_value.to_string()
                 };
 
-                return format!("{}{}", acc, regex_value);
+                format!("{}{}", acc, regex_value)
             },
         );
 
diff --git a/src/detections/utils.rs b/src/detections/utils.rs
index bfad4c46..4dc2fed9 100644
--- a/src/detections/utils.rs
+++ b/src/detections/utils.rs
@@ -276,7 +276,7 @@ fn create_recordinfos(record: &Value) -> String {
     let summary: Vec<String> = output
         .iter()
         .map(|(key, value)| {
-            return format!("{}:{}", key, value);
+            format!("{}:{}", key, value)
         })
         .collect();
 
@@ -314,7 +314,7 @@ fn _collect_recordinfo<'a>(
                     continue;
                 }
                 // Event.Systemは出力しない
-                if key.eq("System") && keys.get(0).unwrap_or(&"").eq(&"Event") {
+                if key.eq("System") && keys.first().unwrap_or(&"").eq(&"Event") {
                     continue;
                 }
 
diff --git a/src/timeline/timelines.rs b/src/timeline/timelines.rs
index 20e1ea77..420aaf8b 100644
--- a/src/timeline/timelines.rs
+++ b/src/timeline/timelines.rs
@@ -35,11 +35,12 @@ impl Timeline {
     }
 
     pub fn tm_stats_dsp_msg(&mut self) {
-        if !configs::CONFIG
-            .read()
-            .unwrap()
-            .args
-            .is_present("statistics")
+        let statics_flag = configs::CONFIG
+        .read()
+        .unwrap()
+        .args
+        .is_present("statistics");
+        if ! statics_flag
         {
             return;
         }
@@ -70,11 +71,12 @@ impl Timeline {
     }
 
     pub fn tm_logon_stats_dsp_msg(&mut self) {
-        if !configs::CONFIG
-            .read()
-            .unwrap()
-            .args
-            .is_present("logon-summary")
+        let logon_summary_flag = configs::CONFIG
+        .read()
+        .unwrap()
+        .args
+        .is_present("logon-summary");
+        if !logon_summary_flag
         {
             return;
         }