diff --git a/client/cmdlf.c b/client/cmdlf.c
index 9dfa16640..3243d60af 100644
--- a/client/cmdlf.c
+++ b/client/cmdlf.c
@@ -189,9 +189,6 @@ int CmdLFCommandRead(const char *Cmd) {
 int CmdFlexdemod(const char *Cmd) {
     (void)Cmd; // Cmd is not used so far
 
-    if (GraphTraceLen < 0)
-        return 0;
-
 #ifndef LONG_WAIT
 #define LONG_WAIT 100
 #endif
diff --git a/client/proxguiqt.cpp b/client/proxguiqt.cpp
index 2cf2d0200..e2ef546f6 100644
--- a/client/proxguiqt.cpp
+++ b/client/proxguiqt.cpp
@@ -276,9 +276,11 @@ QColor Plot::getColor(int graphNum) {
 
 void Plot::setMaxAndStart(int *buffer, size_t len, QRect plotRect) {
     if (len == 0) return;
-    startMax = (len - (int)((plotRect.right() - plotRect.left() - 40) / GraphPixelsPerPoint));
-    if (startMax < 0) {
-        startMax = 0;
+    startMax = 0;
+    if (plotRect.right() >= plotRect.left() + 40) {
+        uint32_t t = (plotRect.right() - plotRect.left() - 40) / GraphPixelsPerPoint;
+        if (len >= t)
+            startMax = len - t;
     }
     if (GraphStart > startMax) {
         GraphStart = startMax;
@@ -470,9 +472,6 @@ void Plot::paintEvent(QPaintEvent *event) {
 
     painter.setFont(QFont("Courier New", 10));
 
-    if (GraphStart < 0)
-        GraphStart = 0;
-
     if (CursorAPos > GraphTraceLen)
         CursorAPos = 0;
     if (CursorBPos > GraphTraceLen)