diff --git a/plugins/git4idea/src/git4idea/repo/GitRepositoryReader.java b/plugins/git4idea/src/git4idea/repo/GitRepositoryReader.java
index 8370f2ed1ed0..06a32c52e434 100644
--- a/plugins/git4idea/src/git4idea/repo/GitRepositoryReader.java
+++ b/plugins/git4idea/src/git4idea/repo/GitRepositoryReader.java
@@ -31,6 +31,7 @@ import com.intellij.vcs.log.Hash;
 import com.intellij.vcs.log.impl.HashImpl;
 import git4idea.*;
 import git4idea.branch.GitBranchUtil;
+import git4idea.validators.GitRefNameValidator;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -272,7 +273,7 @@ class GitRepositoryReader {
           if (relativePath != null) {
             String branchName = prefix + FileUtil.toSystemIndependentName(relativePath);
             String hash = loadHashFromBranchFile(file);
-            if (hash != null) {
+            if (hash != null && GitRefNameValidator.getInstance().checkInput(branchName)) {
               result.put(branchName, hash);
             }
           }
diff --git a/plugins/git4idea/tests/git4idea/repo/GitRepositoryReaderNewTest.kt b/plugins/git4idea/tests/git4idea/repo/GitRepositoryReaderNewTest.kt
index 12c6c79de260..7d5154365a98 100644
--- a/plugins/git4idea/tests/git4idea/repo/GitRepositoryReaderNewTest.kt
+++ b/plugins/git4idea/tests/git4idea/repo/GitRepositoryReaderNewTest.kt
@@ -19,13 +19,11 @@ import com.intellij.dvcs.repo.Repository.State
 import com.intellij.openapi.util.SystemInfo
 import git4idea.GitLocalBranch
 import git4idea.branch.GitBranchUtil
+import git4idea.test.*
 import git4idea.test.GitScenarios.commit
 import git4idea.test.GitScenarios.conflict
-import git4idea.test.GitSingleRepoTest
-import git4idea.test.makeCommit
-import git4idea.test.git
-import git4idea.test.last
 import org.junit.Assume.assumeTrue
+import java.io.File
 import kotlin.test.assertNotEquals
 
 /**
@@ -153,6 +151,14 @@ class GitRepositoryReaderNewTest : GitSingleRepoTest() {
     assertNotEquals(GitLocalBranch("UpperCase"), GitLocalBranch("uppercase"))
   }
 
+  fun `test non-branch files are ignored`() {
+    tac("f.txt")
+    assertTrue(File(myRepo.repositoryFiles.refsHeadsFile, "master.lock").createNewFile())
+
+    myRepo.update()
+    assertSameElements(listOf("master"), myRepo.branches.localBranches.map { it.name })
+  }
+
   private fun moveToDetachedHead(): String {
     makeCommit("file.txt")
     makeCommit("file.txt")