diff --git a/du3/program.c b/du3/program.c
index 07b6f92..a0eef17 100644
--- a/du3/program.c
+++ b/du3/program.c
@@ -59,7 +59,7 @@ int main()
 
             char op1 = 'N';  //N = 'None/NIC'
 
-            for (int i = 0; i != '\0'; i++)
+            for (int i = 0; strBuffer[i] != '\0'; i++)
             {
                 if (isdigit(strBuffer[i]) != 0) 
                 {