diff --git a/flows/actions/testdata/send_msg.json b/flows/actions/testdata/send_msg.json
index 341a7facf..e8e63f01a 100644
--- a/flows/actions/testdata/send_msg.json
+++ b/flows/actions/testdata/send_msg.json
@@ -1003,5 +1003,93 @@
             "waiting_exits": [],
             "parent_refs": []
         }
+    },
+    {
+        "description": "Image parameter value ignored if not valid attachment",
+        "action": {
+            "type": "send_msg",
+            "uuid": "ad154980-7bf7-4ab8-8728-545fd6378912",
+            "text": "The Maine Coone is the only native American long haired breed.",
+            "template": {
+                "uuid": "be68beff-1a5b-424b-815e-023cc53c1ddc",
+                "name": "cat_fact"
+            },
+            "template_variables": [
+                "cat",
+                "The first true cats came into existence about 12 million years ago and were the Proailurus."
+            ]
+        },
+        "events": [
+            {
+                "type": "msg_created",
+                "created_on": "2018-10-18T14:20:30.000123456Z",
+                "step_uuid": "59d74b86-3e2f-4a93-aece-b05d2fdcde0c",
+                "msg": {
+                    "uuid": "9688d21d-95aa-4bed-afc7-f31b35731a3d",
+                    "urn": "tel:+12065551212?channel=57f1078f-88aa-46f4-a59a-948a5739c03d&id=123",
+                    "channel": {
+                        "uuid": "57f1078f-88aa-46f4-a59a-948a5739c03d",
+                        "name": "My Android Phone"
+                    },
+                    "text": "The first true cats came into existence about 12 million years ago and were the Proailurus.",
+                    "templating": {
+                        "template": {
+                            "uuid": "be68beff-1a5b-424b-815e-023cc53c1ddc",
+                            "name": "cat_fact"
+                        },
+                        "components": [
+                            {
+                                "name": "header",
+                                "type": "header/media",
+                                "variables": {
+                                    "1": 0
+                                }
+                            },
+                            {
+                                "name": "body",
+                                "type": "body/text",
+                                "variables": {
+                                    "1": 1
+                                }
+                            }
+                        ],
+                        "variables": [
+                            {
+                                "type": "image",
+                                "value": "cat"
+                            },
+                            {
+                                "type": "text",
+                                "value": "The first true cats came into existence about 12 million years ago and were the Proailurus."
+                            }
+                        ]
+                    },
+                    "locale": "eng-US"
+                }
+            }
+        ],
+        "templates": [
+            "The Maine Coone is the only native American long haired breed.",
+            "cat",
+            "The first true cats came into existence about 12 million years ago and were the Proailurus."
+        ],
+        "localizables": [
+            "The Maine Coone is the only native American long haired breed.",
+            "cat",
+            "The first true cats came into existence about 12 million years ago and were the Proailurus."
+        ],
+        "inspection": {
+            "dependencies": [
+                {
+                    "uuid": "be68beff-1a5b-424b-815e-023cc53c1ddc",
+                    "name": "cat_fact",
+                    "type": "template"
+                }
+            ],
+            "issues": [],
+            "results": [],
+            "waiting_exits": [],
+            "parent_refs": []
+        }
     }
 ]
\ No newline at end of file
diff --git a/flows/template.go b/flows/template.go
index e04df3e6e..2be5d0fe8 100644
--- a/flows/template.go
+++ b/flows/template.go
@@ -103,7 +103,7 @@ func (t *TemplateTranslation) Preview(vars []*TemplatingVariable) *MsgContent {
 
 			if variable.Type == "text" {
 				content = strings.ReplaceAll(content, fmt.Sprintf("{{%s}}", key), variable.Value)
-			} else if variable.Type == "image" || variable.Type == "video" || variable.Type == "document" {
+			} else if (variable.Type == "image" || variable.Type == "video" || variable.Type == "document") && utils.IsValidAttachment(variable.Value) {
 				attachments = append(attachments, utils.Attachment(variable.Value))
 			}
 		}
diff --git a/utils/attachment.go b/utils/attachment.go
index e7c684737..9c75fc496 100644
--- a/utils/attachment.go
+++ b/utils/attachment.go
@@ -42,3 +42,9 @@ func (a Attachment) URL() string {
 	_, url := a.ToParts()
 	return url
 }
+
+// IsValidAttachment returns whether the given string is a valid attachment
+func IsValidAttachment(s string) bool {
+	typ, url := Attachment(s).ToParts()
+	return typ != "" && url != ""
+}
diff --git a/utils/attachment_test.go b/utils/attachment_test.go
index b9705ee31..7eca6996a 100644
--- a/utils/attachment_test.go
+++ b/utils/attachment_test.go
@@ -14,27 +14,29 @@ func TestAttachment(t *testing.T) {
 	assert.Equal(t, "image/jpeg", attachment.ContentType())
 	assert.Equal(t, "https://example.com/test.jpg", attachment.URL())
 
-	assertParse := func(a string, expectedType, expectedURL string) {
+	assertParse := func(a string, expectedType, expectedURL string, isValid bool) {
 		actualType, actualURL := utils.Attachment(a).ToParts()
 		assert.Equal(t, expectedType, actualType, "content type mismatch for attachment '%s'", a)
 		assert.Equal(t, expectedURL, actualURL, "content type mismatch for attachment '%s'", a)
+		assert.Equal(t, isValid, utils.IsValidAttachment(a), "is valid mismatch for attachment '%s'", a)
 	}
 
-	assertParse("audio:http://test.m4a", "audio", "http://test.m4a")
-	assertParse("audio/mp4:http://test.m4a", "audio/mp4", "http://test.m4a")
-	assertParse("audio:/file/path", "audio", "/file/path")
+	assertParse("audio:http://test.m4a", "audio", "http://test.m4a", true)
+	assertParse("audio/mp4:http://test.m4a", "audio/mp4", "http://test.m4a", true)
+	assertParse("audio:/file/path", "audio", "/file/path", true)
 
-	assertParse("application:http://test.pdf", "application", "http://test.pdf")
-	assertParse("application/pdf:http://test.pdf", "application/pdf", "http://test.pdf")
+	assertParse("application:http://test.pdf", "application", "http://test.pdf", true)
+	assertParse("application/pdf:http://test.pdf", "application/pdf", "http://test.pdf", true)
 
-	assertParse("geo:-2.90875,-79.0117686", "geo", "-2.90875,-79.0117686")
+	assertParse("geo:-2.90875,-79.0117686", "geo", "-2.90875,-79.0117686", true)
 
-	assertParse("unavailable:http://bad.link", "unavailable", "http://bad.link")
+	assertParse("unavailable:http://bad.link", "unavailable", "http://bad.link", true)
 
 	// be lenient with invalid attachments
-	assertParse("foo", "", "foo")
-	assertParse("http://test.jpg", "", "http://test.jpg")
-	assertParse("https://test.jpg", "", "https://test.jpg")
-	assertParse("HTTPS://test.jpg", "", "HTTPS://test.jpg")
-	assertParse(":http://test.jpg", "", ":http://test.jpg")
+	assertParse("", "", "", false)
+	assertParse("foo", "", "foo", false)
+	assertParse("http://test.jpg", "", "http://test.jpg", false)
+	assertParse("https://test.jpg", "", "https://test.jpg", false)
+	assertParse("HTTPS://test.jpg", "", "HTTPS://test.jpg", false)
+	assertParse(":http://test.jpg", "", ":http://test.jpg", false)
 }