diff --git a/ChangeLog.txt b/ChangeLog.txt
index 203c27fb..aa07c672 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -1,3 +1,6 @@
+Client library:
+- Don't treat an unexpected PUBREL as a fatal error. Issue #1629.
+
 Build:
 - Various fixes for building with <C99 support. Closes #1622.
 - Fix use of sed on BSD. Closes #1614.
diff --git a/lib/handle_pubrel.c b/lib/handle_pubrel.c
index b42bd63f..060e7c0d 100644
--- a/lib/handle_pubrel.c
+++ b/lib/handle_pubrel.c
@@ -101,9 +101,7 @@ int handle__pubrel(struct mosquitto_db *db, struct mosquitto *mosq)
 	}
 
 	rc = message__remove(mosq, mid, mosq_md_in, &message, 2);
-	if(rc){
-		return rc;
-	}else{
+	if(rc == MOSQ_ERR_SUCCESS){
 		/* Only pass the message on if we have removed it from the queue - this
 		 * prevents multiple callbacks for the same message. */
 		pthread_mutex_lock(&mosq->callback_mutex);
@@ -120,6 +118,10 @@ int handle__pubrel(struct mosquitto_db *db, struct mosquitto *mosq)
 		pthread_mutex_unlock(&mosq->callback_mutex);
 		mosquitto_property_free_all(&properties);
 		message__cleanup(&message);
+	}else if(rc == MOSQ_ERR_NOT_FOUND){
+		return MOSQ_ERR_SUCCESS;
+	}else{
+		return rc;
 	}
 #endif
 
diff --git a/test/lib/Makefile b/test/lib/Makefile
index 3462e252..941bf02d 100644
--- a/test/lib/Makefile
+++ b/test/lib/Makefile
@@ -41,6 +41,7 @@ c : test-compile
 	./03-publish-b2c-qos1.py $@/03-publish-b2c-qos1.test
 	./03-publish-b2c-qos2-len.py $@/03-publish-b2c-qos2-len.test
 	./03-publish-b2c-qos2.py $@/03-publish-b2c-qos2.test
+	./03-publish-b2c-qos2-unexpected-pubrel.py $@/03-publish-b2c-qos2-unexpected-pubrel.test
 	./03-publish-c2b-qos1-disconnect.py $@/03-publish-c2b-qos1-disconnect.test
 	./03-publish-c2b-qos1-len.py $@/03-publish-c2b-qos1-len.test
 	./03-publish-c2b-qos1-receive-maximum.py $@/03-publish-c2b-qos1-receive-maximum.test
diff --git a/test/lib/c/03-publish-b2c-qos2-unexpected-pubrel.c b/test/lib/c/03-publish-b2c-qos2-unexpected-pubrel.c
new file mode 100644
index 00000000..091a6045
--- /dev/null
+++ b/test/lib/c/03-publish-b2c-qos2-unexpected-pubrel.c
@@ -0,0 +1,72 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <mosquitto.h>
+
+static int run = -1;
+
+void on_connect(struct mosquitto *mosq, void *obj, int rc)
+{
+	if(rc){
+		exit(1);
+	}
+}
+
+void on_message(struct mosquitto *mosq, void *obj, const struct mosquitto_message *msg)
+{
+	if(msg->mid != 13423){
+		printf("Invalid mid (%d)\n", msg->mid);
+		exit(1);
+	}
+	if(msg->qos != 2){
+		printf("Invalid qos (%d)\n", msg->qos);
+		exit(1);
+	}
+	if(strcmp(msg->topic, "pub/qos2/receive")){
+		printf("Invalid topic (%s)\n", msg->topic);
+		exit(1);
+	}
+	if(strcmp(msg->payload, "message")){
+		printf("Invalid payload (%s)\n", (char *)msg->payload);
+		exit(1);
+	}
+	if(msg->payloadlen != 7){
+		printf("Invalid payloadlen (%d)\n", msg->payloadlen);
+		exit(1);
+	}
+	if(msg->retain != false){
+		printf("Invalid retain (%d)\n", msg->retain);
+		exit(1);
+	}
+
+	run = 0;
+}
+
+int main(int argc, char *argv[])
+{
+	int rc;
+	struct mosquitto *mosq;
+
+	int port = atoi(argv[1]);
+
+	mosquitto_lib_init();
+
+	mosq = mosquitto_new("publish-qos2-test", true, &run);
+	mosquitto_connect_callback_set(mosq, on_connect);
+	mosquitto_message_callback_set(mosq, on_message);
+	mosquitto_message_retry_set(mosq, 5);
+
+	rc = mosquitto_connect(mosq, "localhost", port, 60);
+
+	while(run == -1){
+		rc = mosquitto_loop(mosq, 300, 1);
+		if(rc){
+			printf("%d:%s\n", rc, mosquitto_strerror(rc));
+			exit(1);
+		}
+	}
+
+	mosquitto_lib_cleanup();
+	return run;
+}
diff --git a/test/lib/c/Makefile b/test/lib/c/Makefile
index 79d1fc03..91d5a95c 100644
--- a/test/lib/c/Makefile
+++ b/test/lib/c/Makefile
@@ -27,6 +27,7 @@ SRC = \
 	03-publish-c2b-qos2-disconnect.c \
 	03-publish-c2b-qos2-len.c \
 	03-publish-b2c-qos2-len.c \
+	03-publish-b2c-qos2-unexpected-pubrel.c \
 	03-publish-c2b-qos1-receive-maximum.c \
 	03-publish-c2b-qos2-receive-maximum-1.c \
 	03-publish-c2b-qos2-receive-maximum-2.c \
diff --git a/test/lib/test.py b/test/lib/test.py
index d61b01c0..885055a7 100755
--- a/test/lib/test.py
+++ b/test/lib/test.py
@@ -23,6 +23,7 @@ tests = [
 
     (1, ['./03-publish-b2c-qos1.py', 'c/03-publish-b2c-qos1.test']),
     (1, ['./03-publish-b2c-qos2-len.py', 'c/03-publish-b2c-qos2-len.test']),
+    (1, ['./03-publish-b2c-qos2-unexpected-pubrel.py', 'c/03-publish-b2c-qos2-unexpected-pubrel.test']),
     (1, ['./03-publish-b2c-qos2.py', 'c/03-publish-b2c-qos2.test']),
     (1, ['./03-publish-c2b-qos1-disconnect.py', 'c/03-publish-c2b-qos1-disconnect.test']),
     (1, ['./03-publish-c2b-qos1-len.py', 'c/03-publish-c2b-qos1-len.test']),