diff --git a/src/main/kotlin/io/gitlab/jfronny/sdom/actions/SDStatementAction.kt b/src/main/kotlin/io/gitlab/jfronny/sdom/actions/SDStatementAction.kt
index 7212442..6969110 100644
--- a/src/main/kotlin/io/gitlab/jfronny/sdom/actions/SDStatementAction.kt
+++ b/src/main/kotlin/io/gitlab/jfronny/sdom/actions/SDStatementAction.kt
@@ -59,7 +59,8 @@ class SDStatementAction(name: String) : DumbAwareAction(name) {
         CoroutineScope(Job() + Dispatchers.IO).launch {
             val data = SDom.downloadProblemStatement(contest, problem)
             fun createTmpFile(): Path {
-                val path = Files.createTempFile("${problem.name}_${contest.name}", ".pdf")
+                val prefix = "${problem.name}_${contest.name}".replace("[^a-zA-Z0-9._-]".toRegex(), "_")
+                val path = Files.createTempFile(prefix, ".pdf")
                 Files.write(path, data, StandardOpenOption.WRITE)
                 return path
             }