diff --git a/libsolidity/interface/StandardCompiler.cpp b/libsolidity/interface/StandardCompiler.cpp
index 00662718e..a97114e83 100644
--- a/libsolidity/interface/StandardCompiler.cpp
+++ b/libsolidity/interface/StandardCompiler.cpp
@@ -320,9 +320,9 @@ Json::Value formatImmutableReferences(map<u256, pair<string, vector<size_t>>> co
 		Json::Value array(Json::arrayValue);
 		for (size_t byteOffset: byteOffsets)
 		{
-			Json::Value byteRange(Json::arrayValue);
-			byteRange.append(Json::UInt(byteOffset));
-			byteRange.append(Json::UInt(32)); // immutable references are currently always 32 bytes wide
+			Json::Value byteRange(Json::objectValue);
+			byteRange["start"] = Json::UInt(byteOffset);
+			byteRange["length"] = Json::UInt(32); // immutable references are currently always 32 bytes wide
 			array.append(byteRange);
 		}
 		ret[identifier] = array;
diff --git a/test/cmdlineTests/standard_immutable_references/output.json b/test/cmdlineTests/standard_immutable_references/output.json
index 1ba91eff7..2788a8e73 100644
--- a/test/cmdlineTests/standard_immutable_references/output.json
+++ b/test/cmdlineTests/standard_immutable_references/output.json
@@ -1,2 +1,2 @@
-{"contracts":{"a.sol":{"A":{"evm":{"deployedBytecode":{"immutableReferences":{"3":[[77,32]]},"linkReferences":{},"object":"bytecode removed","opcodes":"opcodes removed","sourceMap":"0:96:0:-:0;;;;5:9:-1;2:2;;;27:1;24;17:12;2:2;0:96:0;;;;;;;;;;;;;;;;12:1:-1;9;2:12;38:56:0;;;:::i;:::-;;;;;;;;;;;;;;;;;;;;72:7;90:1;83:8;;38:56;:::o"}}}}},"errors":[{"component":"general","formattedMessage":"a.sol: Warning: Source file does not specify required compiler version!
+{"contracts":{"a.sol":{"A":{"evm":{"deployedBytecode":{"immutableReferences":{"3":[{"length":32,"start":77}]},"linkReferences":{},"object":"bytecode removed","opcodes":"opcodes removed","sourceMap":"0:96:0:-:0;;;;5:9:-1;2:2;;;27:1;24;17:12;2:2;0:96:0;;;;;;;;;;;;;;;;12:1:-1;9;2:12;38:56:0;;;:::i;:::-;;;;;;;;;;;;;;;;;;;;72:7;90:1;83:8;;38:56;:::o"}}}}},"errors":[{"component":"general","formattedMessage":"a.sol: Warning: Source file does not specify required compiler version!
 ","message":"Source file does not specify required compiler version!","severity":"warning","sourceLocation":{"end":-1,"file":"a.sol","start":-1},"type":"Warning"}],"sources":{"a.sol":{"id":0}}}