diff --git a/Cargo.lock b/Cargo.lock
index 4630a7d..1a7838f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1008,6 +1008,7 @@ version = "1.0.145"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "402a6f66d8c709116cf22f558eab210f5a50187f702eb4d7e5ef38d9a7f1c79c"
 dependencies = [
+ "indexmap",
  "itoa",
  "memchr",
  "ryu",
diff --git a/Cargo.toml b/Cargo.toml
index 52e6f55..f3cdbcc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,6 +18,6 @@ reqwest = { version = "0.12", default-features = false, features = ["blocking",
 clap = { version = "4.5.43", features = ["derive"] }
 serde = { version = "1.0.219", features = ["derive"] }
 csv = "1.3.0"
-serde_json = "1.0"
+serde_json = { version = "1.0", features = ["preserve_order"] }
 indexmap = "2.9.0"
 clap_complete = "4.5"
diff --git a/src/measurements.rs b/src/measurements.rs
index 49a9dd3..9ba252c 100644
--- a/src/measurements.rs
+++ b/src/measurements.rs
@@ -101,22 +101,22 @@ fn compose_output_json(
     metadata: Option<&Metadata>,
 ) -> serde_json::Map<String, serde_json::Value> {
     let mut output = serde_json::Map::new();
-    output.insert(
-        "speed_measurements".to_string(),
-        serde_json::to_value(stat_measurements).unwrap(),
-    );
-    if let Some(latency) = latency_measurement {
-        output.insert(
-            "latency_measurement".to_string(),
-            serde_json::to_value(latency).unwrap(),
-        );
-    }
     if let Some(metadata) = metadata {
         output.insert(
             "metadata".to_string(),
             serde_json::to_value(metadata).unwrap(),
         );
     }
+    if let Some(latency) = latency_measurement {
+        output.insert(
+            "latency_measurement".to_string(),
+            serde_json::to_value(latency).unwrap(),
+        );
+    }
+    output.insert(
+        "speed_measurements".to_string(),
+        serde_json::to_value(stat_measurements).unwrap(),
+    );
     output
 }
 
@@ -379,5 +379,11 @@ mod tests {
 
         assert!(output.get("latency_measurement").is_some());
         assert!(output.get("speed_measurements").is_some());
+
+        let keys: Vec<&str> = output.keys().map(String::as_str).collect();
+        assert_eq!(
+            keys,
+            vec!["metadata", "latency_measurement", "speed_measurements"]
+        );
     }
 }