diff --git a/utils.go b/utils.go
index 1995971..292b89e 100644
--- a/utils.go
+++ b/utils.go
@@ -879,7 +879,7 @@ func pollMemoryUsage(pid int, interval time.Duration, done chan bool, peakMem *i
 			}
 
 			totalMemory := totalRSS + totalSwap
-			if totalMemory > *peakMem {
+			if peakMem == nil || totalMemory > *peakMem {
 				peakMem = &totalMemory
 			}