diff --git a/dpf/dgl/src/ImageWidgets.cpp b/dpf/dgl/src/ImageWidgets.cpp
index de94ca02..94bf58a1 100644
--- a/dpf/dgl/src/ImageWidgets.cpp
+++ b/dpf/dgl/src/ImageWidgets.cpp
@@ -612,8 +612,9 @@ bool ImageKnob::onScroll(const ScrollEvent& ev)
     if (! contains(ev.pos))
         return false;
 
+    const float dir   = (ev.delta.getY() > 0.f) ? 1.f : -1.f;
     const float d     = (ev.mod & kModifierControl) ? 2000.0f : 200.0f;
-    float       value = (fUsingLog ? _invlogscale(fValueTmp) : fValueTmp) + (float(fMaximum - fMinimum) / d * 10.f * ev.delta.getY());
+    float       value = (fUsingLog ? _invlogscale(fValueTmp) : fValueTmp) + (float(fMaximum - fMinimum) / d * 10.f * dir);
 
     if (fUsingLog)
         value = _logscale(value);