diff --git a/src/cluster_reader.c b/src/cluster_reader.c
index fc953ff..2166cff 100644
--- a/src/cluster_reader.c
+++ b/src/cluster_reader.c
@@ -192,7 +192,7 @@ int analyze_data(int32_t *data, int32_t *t2, int32_t *t3, char *quad,
 
     int32_t tot2[4];
     int32_t t2max = 0;
-    char c;
+    char c = 0;
     int32_t val, tot3;
 
     tot3 = 0;