diff --git a/src/libecoPCR/ecoseq.c b/src/libecoPCR/ecoseq.c
index 10bb68a..1368be9 100644
--- a/src/libecoPCR/ecoseq.c
+++ b/src/libecoPCR/ecoseq.c
@@ -100,6 +100,8 @@ ecoseq_t *readnext_ecoseq(FILE *f)
 	int32_t  comp_status;
 	unsigned long int seqlength;
 	int32_t  rs;
+	char *c;
+	int32_t i;
 
 	raw = read_ecorecord(f,&rs);
 
@@ -144,6 +146,9 @@ ecoseq_t *readnext_ecoseq(FILE *f)
     if (comp_status != Z_OK)
     	ECOERROR(ECO_IO_ERROR,"I cannot uncompress sequence data");
 
+    for (c=seq->SQ,i=0;i<seqlength;c++,i++)
+    	*c=toupper(*c);
+
 //	fprintf(stderr,"seq name : %30s seq size : %d\n",seq->DE,seq->SQ_length);
 	return seq;
 }