diff --git a/src/main/java/io/spring/projectapi/web/webhook/CacheController.java b/src/main/java/io/spring/projectapi/web/webhook/CacheController.java
index b39a132..5538398 100644
--- a/src/main/java/io/spring/projectapi/web/webhook/CacheController.java
+++ b/src/main/java/io/spring/projectapi/web/webhook/CacheController.java
@@ -63,6 +63,8 @@ public class CacheController {
 
 	private static final String PING_EVENT = "ping";
 
+	private static final String MAIN_BRANCH = "refs/heads/main";
+
 	private final ObjectMapper objectMapper;
 
 	private final Mac hmac;
@@ -100,6 +102,9 @@ public ResponseEntity<String> refresh(@RequestBody String payload,
 		}
 		Map<?, ?> push = this.objectMapper.readValue(payload, Map.class);
 		logPayload(push);
+		if (!push.get("ref").equals(MAIN_BRANCH)) {
+			return ResponseEntity.ok("{ \"message\": \"Push event not on main\" }");
+		}
 		List<Map<String, ?>> commits = (List<Map<String, ?>>) push.get("commits");
 		List<String> changes = getChangedFiles(commits);
 		this.repository.update(changes);
diff --git a/src/test/java/io/spring/projectapi/web/webhook/CacheControllerTests.java b/src/test/java/io/spring/projectapi/web/webhook/CacheControllerTests.java
index ea64533..9372bca 100644
--- a/src/test/java/io/spring/projectapi/web/webhook/CacheControllerTests.java
+++ b/src/test/java/io/spring/projectapi/web/webhook/CacheControllerTests.java
@@ -37,6 +37,7 @@
 
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoInteractions;
 
 /**
  * Tests for {@link CacheController}.
@@ -103,18 +104,32 @@ void invalidJsonPushEventShouldBeRejected() throws Exception {
 	}
 
 	@Test
-	void shouldTriggerCacheRefresh() throws Exception {
+	void cacheRefreshNotTriggeredOnBranchOtherThanMain() throws Exception {
 		this.mockMvc
 			.perform(MockMvcRequestBuilders.post("/refresh_cache")
 				.accept(MediaType.APPLICATION_JSON)
 				.contentType(MediaType.APPLICATION_JSON)
 				.header("X-Hub-Signature", "sha1=C8D5B1C972E8DCFB69AB7124678D4C91E11D6F23")
 				.header("X-GitHub-Event", "push")
+				.content(getTestPayload("push_other_branch")))
+			.andExpect(MockMvcResultMatchers.status().isOk())
+			.andExpect(MockMvcResultMatchers.content().string("{ \"message\": \"Push event not on main\" }"));
+		verifyNoInteractions(this.projectRepository);
+	}
+
+	@Test
+	void shouldTriggerCacheRefresh() throws Exception {
+		this.mockMvc
+			.perform(MockMvcRequestBuilders.post("/refresh_cache")
+				.accept(MediaType.APPLICATION_JSON)
+				.contentType(MediaType.APPLICATION_JSON)
+				.header("X-Hub-Signature", "sha1=E1C54005D92AE14A76A7C0CD164AEAC6E6740C64")
+				.header("X-GitHub-Event", "push")
 				.content(getTestPayload("push")))
 			.andExpect(MockMvcResultMatchers.status().isOk())
 			.andExpect(MockMvcResultMatchers.content()
 				.string("{ \"message\": \"Successfully processed cache refresh\" }"));
-		verify(this.projectRepository, times(1)).update(List.of("index-common.html"));
+		verify(this.projectRepository, times(1)).update(List.of("added.html", "index-common.html"));
 	}
 
 	private String getTestPayload(String fileName) throws Exception {
diff --git a/src/test/resources/io/spring/projectapi/web/webhook/push.json b/src/test/resources/io/spring/projectapi/web/webhook/push.json
index d9c8a86..dac9b2e 100644
--- a/src/test/resources/io/spring/projectapi/web/webhook/push.json
+++ b/src/test/resources/io/spring/projectapi/web/webhook/push.json
@@ -1,5 +1,5 @@
 {
-  "ref": "refs/heads/master",
+  "ref": "refs/heads/main",
   "after": "a427f3f4db6c96ae5e86b610d0eef149393c9996",
   "before": "3193db21394092a84d973bef8c4a3741aec1b814",
   "created": false,
@@ -24,6 +24,7 @@
         "username": "cbeams"
       },
       "added": [
+        "added.html"
       ],
       "removed": [
       ],
diff --git a/src/test/resources/io/spring/projectapi/web/webhook/push_other_branch.json b/src/test/resources/io/spring/projectapi/web/webhook/push_other_branch.json
new file mode 100644
index 0000000..d9c8a86
--- /dev/null
+++ b/src/test/resources/io/spring/projectapi/web/webhook/push_other_branch.json
@@ -0,0 +1,112 @@
+{
+  "ref": "refs/heads/master",
+  "after": "a427f3f4db6c96ae5e86b610d0eef149393c9996",
+  "before": "3193db21394092a84d973bef8c4a3741aec1b814",
+  "created": false,
+  "deleted": false,
+  "forced": false,
+  "compare": "https://github.com/spring-guides/gs-test-guide/compare/3193db213940...a427f3f4db6c",
+  "commits": [
+    {
+      "id": "6bdc0feaec5ccc85a9c4fe2a3e62bebe5a69e8fc",
+      "distinct": true,
+      "message": "Touch index-common to trigger gh-pages build",
+      "timestamp": "2013-08-10T15:56:23-07:00",
+      "url": "https://github.com/spring-projects/gs-test-guide/commit/6bdc0feaec5ccc85a9c4fe2a3e62bebe5a69e8fc",
+      "author": {
+        "name": "Chris Beams",
+        "email": "cbeams@gopivotal.com",
+        "username": "cbeams"
+      },
+      "committer": {
+        "name": "Chris Beams",
+        "email": "cbeams@gopivotal.com",
+        "username": "cbeams"
+      },
+      "added": [
+      ],
+      "removed": [
+      ],
+      "modified": [
+        "index-common.html"
+      ]
+    },
+    {
+      "id": "a427f3f4db6c96ae5e86b610d0eef149393c9996",
+      "distinct": true,
+      "message": "Remove empty newline at end of index-common",
+      "timestamp": "2013-08-10T16:12:39-07:00",
+      "url": "https://github.com/spring-guides/gs-test-guide/commit/a427f3f4db6c96ae5e86b610d0eef149393c9996",
+      "author": {
+        "name": "Chris Beams",
+        "email": "cbeams@gopivotal.com",
+        "username": "cbeams"
+      },
+      "committer": {
+        "name": "Chris Beams",
+        "email": "cbeams@gopivotal.com",
+        "username": "cbeams"
+      },
+      "added": [
+      ],
+      "removed": [
+      ],
+      "modified": [
+        "index-common.html"
+      ]
+    }
+  ],
+  "head_commit": {
+    "id": "a427f3f4db6c96ae5e86b610d0eef149393c9996",
+    "distinct": true,
+    "message": "Remove empty newline at end of index-common",
+    "timestamp": "2013-08-10T16:12:39-07:00",
+    "url": "https://github.com/spring-guides/gs-test-guide/commit/a427f3f4db6c96ae5e86b610d0eef149393c9996",
+    "author": {
+      "name": "Chris Beams",
+      "email": "cbeams@gopivotal.com",
+      "username": "cbeams"
+    },
+    "committer": {
+      "name": "Chris Beams",
+      "email": "cbeams@gopivotal.com",
+      "username": "cbeams"
+    },
+    "added": [
+    ],
+    "removed": [
+    ],
+    "modified": [
+      "index-common.html"
+    ]
+  },
+  "repository": {
+    "id": 11634233,
+    "name": "gs-test-guide",
+    "url": "https://github.com/spring-guides/gs-test-guide",
+    "description": "A test guide",
+    "homepage": "",
+    "watchers": 0,
+    "stargazers": 0,
+    "forks": 0,
+    "fork": false,
+    "size": 452,
+    "owner": {
+      "name": "spring-guides",
+      "email": null
+    },
+    "private": false,
+    "open_issues": 0,
+    "has_issues": true,
+    "has_downloads": true,
+    "has_wiki": true,
+    "language": "Java",
+    "created_at": 1374668910,
+    "pushed_at": 1376176368,
+    "master_branch": "master",
+    "organization": "spring-guides"
+  },
+  "pusher": {
+    "name": "none"
+  }
+}
\ No newline at end of file