diff --git a/plugins/ImageReader/ConfigUI.qml b/plugins/ImageReader/ConfigUI.qml
index a7dbc5f748..a3dceed50d 100644
--- a/plugins/ImageReader/ConfigUI.qml
+++ b/plugins/ImageReader/ConfigUI.qml
@@ -43,7 +43,7 @@ UM.Dialog
                 TextField {
                     id: peak_height
                     objectName: "Peak_Height"
-                    validator: RegExpValidator {regExp: /^\d{1,3}([\,|\.]\d*)?$/}
+                    validator: RegExpValidator {regExp: /^\d{0,3}([\,|\.]\d*)?$/}
                     width: 180 * screenScaleFactor
                     onTextChanged: { manager.onPeakHeightChanged(text) }
                 }
@@ -66,7 +66,7 @@ UM.Dialog
                 TextField {
                     id: base_height
                     objectName: "Base_Height"
-                    validator: RegExpValidator {regExp: /^\d{1,3}([\,|\.]\d*)?$/}
+                    validator: RegExpValidator {regExp: /^\d{0,3}([\,|\.]\d*)?$/}
                     width: 180 * screenScaleFactor
                     onTextChanged: { manager.onBaseHeightChanged(text) }
                 }