diff --git a/R/puc.R b/R/puc.R
index 85909ad..0e9237d 100644
--- a/R/puc.R
+++ b/R/puc.R
@@ -19,7 +19,7 @@ calcPUC <- function(data) {
     p <- pid(z=z, x1 = data[, ind1], x2 = data[, ind2])
     mi1 <- (p$unique_x1 + p$redundancy)
     mi2 <- (p$unique_x2 + p$redundancy)
-    c( p$unique_x1 / mi1, p$unique_x2 / mi2)
+    c( ifelse(mi1 > 0, p$unique_x1 / mi1, 0), ifelse(mi2 > 0, p$unique_x2 / mi2, 0))
   }
 
   # Efficient calculation of PUC values for all gene triplets