diff --git a/openbr/plugins/hist.cpp b/openbr/plugins/hist.cpp
index b3efd8b..d13fdee 100644
--- a/openbr/plugins/hist.cpp
+++ b/openbr/plugins/hist.cpp
@@ -52,8 +52,12 @@ class HistTransform : public UntrainableTransform
             int histSize[] = {dims};
             float range[] = {min, max};
             const float* ranges[] = {range};
-            Mat hist;
-            calcHist(&mv[i], 1, channels, Mat(), hist, 1, histSize, ranges);
+            Mat hist, chan = mv[i];
+            // calcHist requires F or U, might as well convert just in case
+            if (mv[i].depth() != CV_8U || mv[i].depth() == CV_32F)
+                mv[i].convertTo(chan, CV_32FC1);
+//            qDebug("clust r %i c %i ch %i", chan.rows, chan.cols, chan.channels());
+            calcHist(&chan, 1, channels, Mat(), hist, 1, histSize, ranges);
             memcpy(m.ptr(i), hist.ptr(), dims * sizeof(float));
         }