diff --git a/python/obitools3/commands/ecopcr.pyx b/python/obitools3/commands/ecopcr.pyx
index 8228a1c..240930e 100755
--- a/python/obitools3/commands/ecopcr.pyx
+++ b/python/obitools3/commands/ecopcr.pyx
@@ -35,13 +35,13 @@ def addOptions(parser):
                        action="store", dest="ecopcr:primer1",
                        metavar='<PRIMER>',
                        type=str,
-                       help="Forward primer.")
+                       help="Forward primer, length must be less than or equal to 32")
 
     group.add_argument('--primer2', '-R',
                        action="store", dest="ecopcr:primer2",
                        metavar='<PRIMER>',
                        type=str,
-                       help="Reverse primer.")
+                       help="Reverse primer, length must be less than or equal to 32")
 
     group.add_argument('--error', '-e',
                        action="store", dest="ecopcr:error",
@@ -203,6 +203,7 @@ def run(config):
     #print("\n\nOutput view:\n````````````", file=sys.stderr)
     #print(repr(o_dms[o_view_name]), file=sys.stderr)
 
-    o_dms.close()
+    i_dms.close(force=True)
+    o_dms.close(force=True)
 
     logger("info", "Done.")
diff --git a/src/obi_ecopcr.c b/src/obi_ecopcr.c
index 994e2f8..1ab7876 100755
--- a/src/obi_ecopcr.c
+++ b/src/obi_ecopcr.c
@@ -739,6 +739,14 @@ int obi_ecopcr(const char* i_dms_name,
 		return -1;
 	}
 
+	// Check primer length (apat lib limits to 32)
+	if ((strlen(primer1) > 32) || (strlen(primer2) > 32))
+	{
+		obi_set_errno(OBI_ECOPCR_ERROR);
+		obidebug(1, "\nError: primer length can not be greater than 32 (primers %s, %s)", primer1, primer2);
+		return -1;
+	}
+
 	o1 = buildPattern(primer1, error_max);
 	o2 = buildPattern(primer2, error_max);
 
diff --git a/src/obi_ecopcr.h b/src/obi_ecopcr.h
index 5ba4c6a..5fa6c7d 100755
--- a/src/obi_ecopcr.h
+++ b/src/obi_ecopcr.h
@@ -81,8 +81,8 @@
  * @param o_dms_name The path to the output DMS.
  * @param o_view_name The name of the output view.
  * @param o_view_comments The comments to associate with the output view.
- * @param primer1 The first primer.
- * @param primer2 The second primer.
+ * @param primer1 The first primer, length must be less than or equal to 32 (because of apat lib limitation).
+ * @param primer2 The second primer, length must be less than or equal to 32 (because of apat lib limitation).
  * @param error_max The maximum number of errors allowed per primer for amplification.
  * @param min_len The minimum length of an amplicon.
  * @param max_len The maximum length of an amplicon.