diff --git a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
index eab7211e18973..e1806d6230a80 100644
--- a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
+++ b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
@@ -219,7 +219,7 @@ bool fromJSON(const json::Value &Params, InitializeRequestArguments &IRA,
          OM.map("clientName", IRA.clientName) && OM.map("locale", IRA.locale) &&
          OM.map("linesStartAt1", IRA.linesStartAt1) &&
          OM.map("columnsStartAt1", IRA.columnsStartAt1) &&
-         OM.map("pathFormat", IRA.pathFormat) &&
+         OM.mapOptional("pathFormat", IRA.pathFormat) &&
          OM.map("$__lldb_sourceInitFile", IRA.lldbExtSourceInitFile);
 }