diff --git a/ChangeLog.txt b/ChangeLog.txt
index 82683352..74967b7b 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -17,6 +17,8 @@ Broker:
 Client library:
 - Set minimum keepalive argument to `mosquitto_connect*()` to be 5 seconds.
   Closes #1550.
+- Fix `mosquitto_topic_matches_sub()` not returning MOSQ_ERR_INVAL if the
+  topic contains a wildcard. Closes #1589.
 
 Clients:
 - Fix `--remove-retained` not obeying the `-T` option for filtering out
diff --git a/lib/util_topic.c b/lib/util_topic.c
index 673cc6ca..ae279467 100644
--- a/lib/util_topic.c
+++ b/lib/util_topic.c
@@ -219,6 +219,9 @@ int mosquitto_topic_matches_sub2(const char *sub, size_t sublen, const char *top
 				spos++;
 				sub++;
 				while(topic[0] != 0 && topic[0] != '/'){
+					if(topic[0] == '+' || topic[0] == '#'){
+						return MOSQ_ERR_INVAL;
+					}
 					topic++;
 				}
 				if(topic[0] == 0 && sub[0] == 0){
@@ -234,6 +237,12 @@ int mosquitto_topic_matches_sub2(const char *sub, size_t sublen, const char *top
 				if(sub[1] != 0){
 					return MOSQ_ERR_INVAL;
 				}else{
+					while(topic[0] != 0){
+						if(topic[0] == '+' || topic[0] == '#'){
+							return MOSQ_ERR_INVAL;
+						}
+						topic++;
+					}
 					*result = true;
 					return MOSQ_ERR_SUCCESS;
 				}
@@ -292,6 +301,12 @@ int mosquitto_topic_matches_sub2(const char *sub, size_t sublen, const char *top
 	if((topic[0] != 0 || sub[0] != 0)){
 		*result = false;
 	}
+	while(topic[0] != 0){
+		if(topic[0] == '+' || topic[0] == '#'){
+			return MOSQ_ERR_INVAL;
+		}
+		topic++;
+	}
 
 	return MOSQ_ERR_SUCCESS;
 }
diff --git a/test/unit/util_topic_test.c b/test/unit/util_topic_test.c
index 88f668a2..b669fcc9 100644
--- a/test/unit/util_topic_test.c
+++ b/test/unit/util_topic_test.c
@@ -20,6 +20,9 @@ static void no_match_helper(int rc_expected, const char *sub, const char *topic)
 
 	rc = mosquitto_topic_matches_sub(sub, topic, &match);
 	CU_ASSERT_EQUAL(rc, rc_expected);
+	if(rc != rc_expected){
+		printf("%d:%d %s:%s\n", rc, rc_expected, sub, topic);
+	}
 	CU_ASSERT_EQUAL(match, false);
 }
 
@@ -135,6 +138,16 @@ static void TEST_invalid_but_matching(void)
 	no_match_helper(MOSQ_ERR_INVAL, "foo/bar#", "foo/bar#");
 
 	no_match_helper(MOSQ_ERR_INVAL, "foo+", "fooa");
+
+	no_match_helper(MOSQ_ERR_INVAL, "foo/+", "foo/+");
+	no_match_helper(MOSQ_ERR_INVAL, "foo/#", "foo/+");
+	no_match_helper(MOSQ_ERR_INVAL, "foo/+", "foo/bar/+");
+	no_match_helper(MOSQ_ERR_INVAL, "foo/#", "foo/bar/+");
+
+	no_match_helper(MOSQ_ERR_INVAL, "foo/+", "foo/#");
+	no_match_helper(MOSQ_ERR_INVAL, "foo/#", "foo/#");
+	no_match_helper(MOSQ_ERR_INVAL, "foo/+", "foo/bar/#");
+	no_match_helper(MOSQ_ERR_INVAL, "foo/#", "foo/bar/#");
 }