diff --git a/lib/src/source_visitor.dart b/lib/src/source_visitor.dart
index a67dba8..319a53e 100644
--- a/lib/src/source_visitor.dart
+++ b/lib/src/source_visitor.dart
@@ -709,45 +709,59 @@
         node.parameters.parameters.last.endToken.next.type == TokenType.COMMA;
 
     if (hasTrailingComma) {
-      // If there is a trailing comma in the argument list, the ")" will be on
-      // its own line, so keep the ":" with it:
+      // Since the ")", "])", or "})" on the preceding line doesn't take up
+      // much space, it looks weird to move the ":" onto it's own line. Instead,
+      // keep it and the first initializer on the current line but add enough
+      // space before it to line it up with any subsequent initializers.
       //
       //     Foo(
       //       parameter,
-      //     ) : super();
+      //     )   : field = value,
+      //           super();
       space();
+      var isOptional =
+          node.parameters.parameters.last.kind != ParameterKind.REQUIRED;
+      if (node.initializers.length > 1) {
+        _writeText(isOptional ? " " : "  ", node.separator.offset);
+      }
+
+      // ":".
+      token(node.separator);
+      space();
+
+      builder.indent(6);
     } else {
       // Shift the itself ":" forward.
       builder.indent(Indent.constructorInitializer);
 
       // If the parameters or initializers split, put the ":" on its own line.
       split();
+
+      // ":".
+      token(node.separator);
+      space();
+
+      // Try to line up the initializers with the first one that follows the ":":
+      //
+      //     Foo(notTrailing)
+      //         : initializer = value,
+      //           super(); // +2 from previous line.
+      //
+      //     Foo(
+      //       trailing,
+      //     ) : initializer = value,
+      //         super(); // +4 from previous line.
+      //
+      // This doesn't work if there is a trailing comma in an optional parameter,
+      // but we don't want to do a weird +5 alignment:
+      //
+      //     Foo({
+      //       trailing,
+      //     }) : initializer = value,
+      //         super(); // Doesn't quite line up. :(
+      builder.indent(2);
     }
 
-    // ":".
-    token(node.separator);
-    space();
-
-    // Try to line up the initializers with the first one that follows the ":":
-    //
-    //     Foo(notTrailing)
-    //         : initializer = value,
-    //           super(); // +2 from previous line.
-    //
-    //     Foo(
-    //       trailing,
-    //     ) : initializer = value,
-    //         super(); // +4 from previous line.
-    //
-    // This doesn't work if there is a trailing comma in an optional parameter,
-    // but we don't want to do a weird +5 alignment:
-    //
-    //     Foo({
-    //       trailing,
-    //     }) : initializer = value,
-    //         super(); // Doesn't quite line up. :(
-    builder.indent(hasTrailingComma ? 4 : 2);
-
     for (var i = 0; i < node.initializers.length; i++) {
       if (i > 0) {
         // Preceding comma.
diff --git a/test/regression/0600/0658.unit b/test/regression/0600/0658.unit
index da3843c..00fc804 100644
--- a/test/regression/0600/0658.unit
+++ b/test/regression/0600/0658.unit
@@ -25,6 +25,6 @@
   Foo({
     Bar bar,
     Baz baz,
-  }) : assert(bar != null),
-      super(baz);
+  })  : assert(bar != null),
+        super(baz);
 }
\ No newline at end of file
diff --git a/test/splitting/constructors.unit b/test/splitting/constructors.unit
index 1fca57a..dc63662 100644
--- a/test/splitting/constructors.unit
+++ b/test/splitting/constructors.unit
@@ -135,10 +135,10 @@
 class A {
   A(
     a,
-  ) : b = 1,
-      super();
+  )   : b = 1,
+        super();
 }
->>>
+>>> extra space after ":" to line up with later initializers
 class A {
   A({a,}):b=1,super(){;}
 }
@@ -146,8 +146,19 @@
 class A {
   A({
     a,
-  }) : b = 1,
-      super() {
+  })  : b = 1,
+        super() {
     ;
   }
+}
+>>> no extra space on a single initializer, even if it splits
+class A {
+  A(a,):parameter = "some very very long param";
+}
+<<<
+class A {
+  A(
+    a,
+  ) : parameter =
+            "some very very long param";
 }
\ No newline at end of file