diff --git a/src/third_party/GMSHLexer.cpp b/src/third_party/GMSHLexer.cpp
index ee400fe..d56fb93 100644
--- a/src/third_party/GMSHLexer.cpp
+++ b/src/third_party/GMSHLexer.cpp
@@ -23,9 +23,12 @@ GMSHToken GMSHLexer::getToken() {
         return GMSHToken::eof;
     }
 
-    while (isspace(lastChar)) {
+    while (isspace(lastChar) && in->good()) {
         advance();
     }
+    if (!in->good()) {
+        return GMSHToken::eof;
+    }
 
     if (lastChar == '$') {
         advance();