diff --git a/src/cpp/ripple/RPCHandler.cpp b/src/cpp/ripple/RPCHandler.cpp
index c633ede404..51c038a037 100644
--- a/src/cpp/ripple/RPCHandler.cpp
+++ b/src/cpp/ripple/RPCHandler.cpp
@@ -913,7 +913,13 @@ Json::Value RPCHandler::doSubmit(Json::Value jvRequest)
 				txJSON["Fee"] = (int) theConfig.FEE_ACCOUNT_CREATE;
 		}
 
-		if (!txJSON.isMember("Paths") && txJSON.isMember("Amount")  && jvRequest.isMember("build_path"))
+		if (txJSON.isMember("Paths") && jvRequest.isMember("build_path"))
+		{
+			// Asking to build a path when providing one is an error.
+			return rpcError(rpcINVALID_PARAMS);
+		}
+
+		if (!txJSON.isMember("Paths") && txJSON.isMember("Amount") && jvRequest.isMember("build_path"))
 		{
 			// Need a ripple path.
 			STPathSet	spsPaths;
@@ -939,6 +945,12 @@ Json::Value RPCHandler::doSubmit(Json::Value jvRequest)
 				saSendMax.setIssuer(raSrcAddressID.getAccountID());
 			}
 
+			if (saSendMax.isNative() && saSend.isNative())
+			{
+				// Asking to build a path for XRP to XRP is an error.
+				return rpcError(rpcINVALID_PARAMS);
+			}
+
 			Pathfinder pf(raSrcAddressID, dstAccountID, saSendMax.getCurrency(), saSendMax.getIssuer(), saSend);
 
 			if (!pf.findPaths(5, 1, spsPaths))