diff --git a/oscar/Graphs/gLineChart.cpp b/oscar/Graphs/gLineChart.cpp
index 2077bdb3..be4bfd6e 100644
--- a/oscar/Graphs/gLineChart.cpp
+++ b/oscar/Graphs/gLineChart.cpp
@@ -401,8 +401,8 @@ void gLineChart::paint(QPainter &painter, gGraph &w, const QRegion &region)
         return;
     }
 
-    actual_min_y = INT_MAX;
-    actual_max_y = -INT_MAX;
+    actual_min_y = (EventDataType)INT_MAX;
+    actual_max_y = -(EventDataType)INT_MAX;
 
     top++;