diff --git a/CHANGELOG b/CHANGELOG
index 2cfc06e..7300fbd 100755
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,4 +1,7 @@
-SIGNAL SERVER CHANGELOG 
+SIGNAL SERVER CHANGELOG
+
+3.21 Beta - 30 Jul 2019 - N9OZB Mods, minor fix
+Fixed a minor bug in the Gzip decoding routines, gzerror() not coming back NULL?
 
 3.20 Beta - 14 Jul 2019 - N9OZB Mods
 1. Added .GZ (Gzip) file processing for .sdf.gz DEM tiles.
diff --git a/src/inputs.cc b/src/inputs.cc
index 284d9a0..4bc4ed2 100644
--- a/src/inputs.cc
+++ b/src/inputs.cc
@@ -1002,8 +1002,8 @@ char *GZfgets(char *output, gzFile gzfd, unsigned length)
 		}
 
 	}
-	if (debug && errmsg != NULL) {
-	        fprintf(stderr, "GZfgets: errmsg = [%s]\n", errmsg);
+	if (debug && (errmsg != NULL) && (gzerr != Z_OK && gzerr != Z_STREAM_END)) {
+	        fprintf(stderr, "GZfgets: gzerr = %d, errmsg = [%s]\n", gzerr, errmsg);
 		fflush(stderr);
 	}
 	return (output);
@@ -1127,8 +1127,8 @@ int LoadSDF_GZ(char *name)
 		if (gzerr != Z_OK || pos == EOF)
 		        return -errno;
 
-		if (debug && errmsg != NULL) {
-		        fprintf(stderr, "LoadSDF_GZ: errmsg = [%s]\n", errmsg);
+		if (debug && (errmsg != NULL) && (gzerr != Z_OK && gzerr != Z_STREAM_END)) {
+		        fprintf(stderr, "LoadSDF_GZ: gzerr = %d, errmsg = [%s]\n", gzerr, errmsg);
 			fflush(stderr);
 		}
 
diff --git a/src/main.cc b/src/main.cc
index 2874003..5884f39 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -1,4 +1,4 @@
-double version = 3.20;
+double version = 3.21;
 /****************************************************************************\
 *  Signal Server: Radio propagation simulator by Alex Farrant QCVS, 2E0TDW   *
 ******************************************************************************