diff --git a/util/src/common.rs b/util/src/common.rs
index a4ba41f82..7ed660f29 100644
--- a/util/src/common.rs
+++ b/util/src/common.rs
@@ -26,30 +26,46 @@ pub use sha3::*;
 
 #[macro_export]
 macro_rules! hash_map {
-	( $( $x:expr => $y:expr ),* ) => {
-		vec![ $( ($x, $y) ),* ].into_iter().collect::<HashMap<_, _>>()
-	}
+	( $( $x:expr => $y:expr ),* ) => {{
+		let mut x = HashMap::new();
+		$(
+			x.insert($x, $y);
+		)*
+		x
+	}}
 }
 
 #[macro_export]
 macro_rules! hash_mapx {
-	( $( $x:expr => $y:expr ),* ) => {
-		vec![ $( ( From::from($x), From::from($y) ) ),* ].into_iter().collect::<HashMap<_, _>>()
-	}
+	( $( $x:expr => $y:expr ),* ) => {{
+		let mut x = HashMap::new();
+		$(
+			x.insert($x.into(), $y.into());
+		)*
+		x
+	}}
 }
 
 #[macro_export]
 macro_rules! map {
-	( $( $x:expr => $y:expr ),* ) => {
-		vec![ $( ($x, $y) ),* ].into_iter().collect::<BTreeMap<_, _>>()
-	}
+	( $( $x:expr => $y:expr ),* ) => {{
+		let mut x = BTreeMap::new();
+		$(
+			x.insert($x, $y);
+		)*
+		x
+	}}
 }
 
 #[macro_export]
 macro_rules! mapx {
-	( $( $x:expr => $y:expr ),* ) => {
-		vec![ $( ( From::from($x), From::from($y) ) ),* ].into_iter().collect::<BTreeMap<_, _>>()
-	}
+	( $( $x:expr => $y:expr ),* ) => {{
+		let mut x = BTreeMap::new();
+		$(
+			x.insert($x.into(), $y.into());
+		)*
+		x
+	}}
 }
 
 #[macro_export]