diff --git a/client/cmdlffdx.c b/client/cmdlffdx.c
index 20f834ce..5677c79d 100644
--- a/client/cmdlffdx.c
+++ b/client/cmdlffdx.c
@@ -137,7 +137,7 @@ int CmdFdxDemod(const char *Cmd){
 
 	//Differential Biphase / di-phase (inverted biphase)
 	//get binary from ask wave
-	if (!ASKbiphaseDemod("0 32 1 0", false)) {
+	if (!ASKbiphaseDemod("0 32 1 100", false)) {
 		if (g_debugMode) PrintAndLog("DEBUG: Error - FDX-B ASKbiphaseDemod failed");
 		return 0;
 	}