diff --git a/cmd/sops/main.go b/cmd/sops/main.go
index 18701f05d..c426a7fa3 100644
--- a/cmd/sops/main.go
+++ b/cmd/sops/main.go
@@ -860,7 +860,14 @@ func jsonValueToTreeInsertableValue(jsonValue string) (interface{}, error) {
 			return nil, common.NewExitError("Invalid --set value format", codes.ErrorInvalidSetFormat)
 		}
 	}
-	return valueToInsert.(sops.TreeBranches)[0], nil
+	// Fix for #461
+	// Attempt conversion to TreeBranches to handle yaml multidoc. If conversion fails it's
+	// most likely a string value, so just return it as-is.
+	values, ok := valueToInsert.(sops.TreeBranches)
+	if !ok {
+		return valueToInsert, nil
+	}
+	return values[0], nil
 }
 
 func extractSetArguments(set string) (path []interface{}, valueToInsert interface{}, err error) {
diff --git a/functional-tests/src/lib.rs b/functional-tests/src/lib.rs
index 01ec5379e..3e00ad4c7 100644
--- a/functional-tests/src/lib.rs
+++ b/functional-tests/src/lib.rs
@@ -260,6 +260,46 @@ b: ba"#
         }
         panic!("Output YAML does not have the expected structure");
     }
+    
+    #[test]
+    fn set_yaml_file_string() {
+        let file_path = prepare_temp_file("test_set_string.yaml",
+                                          r#"a: 2
+b: ba"#
+                                          .as_bytes());
+        Command::new(SOPS_BINARY_PATH)
+            .arg("-e")
+            .arg("-i")
+            .arg(file_path.clone())
+            .output()
+            .expect("Error running sops");
+        Command::new(SOPS_BINARY_PATH)
+            .arg("-e")
+            .arg("-i")
+            .arg("--set")
+            .arg(r#"["a"] "aaa""#)
+            .arg(file_path.clone())
+            .output()
+            .expect("Error running sops");
+        let output = Command::new(SOPS_BINARY_PATH)
+            .arg("-d")
+            .arg("-i")
+            .arg(file_path.clone())
+            .output()
+            .expect("Error running sops");
+        println!("stdout: {}, stderr: {}",
+                 String::from_utf8_lossy(&output.stdout),
+                 String::from_utf8_lossy(&output.stderr));
+        let mut s = String::new();
+        File::open(file_path).unwrap().read_to_string(&mut s).unwrap();
+        let data: Value = serde_yaml::from_str(&s).expect("Error parsing sops's YAML output");
+        if let Value::Mapping(data) = data {
+            let a = data.get(&Value::String("a".to_owned())).unwrap();
+            assert_eq!(a, &Value::String("aaa".to_owned()));
+        } else {
+            panic!("Output JSON does not have the expected structure");
+        }
+    }
 
     #[test]
     fn decrypt_file_no_mac() {