diff --git a/gtsam/discrete/SignatureParser.cpp b/gtsam/discrete/SignatureParser.cpp
index ab259d0ea..2081e1ee1 100644
--- a/gtsam/discrete/SignatureParser.cpp
+++ b/gtsam/discrete/SignatureParser.cpp
@@ -33,6 +33,8 @@ std::optional<Row> static ParseConditional(const std::string& token) {
       // can throw exception
       row.push_back(std::stod(s));
     }
+    // if we ended with a '/' then return false
+    if (token.back() == '/') return false;
   } catch (...) {
     return std::nullopt;
   }
diff --git a/gtsam/discrete/tests/testSignatureParser.cpp b/gtsam/discrete/tests/testSignatureParser.cpp
index 5ae71442e..933d55d8b 100644
--- a/gtsam/discrete/tests/testSignatureParser.cpp
+++ b/gtsam/discrete/tests/testSignatureParser.cpp
@@ -85,11 +85,16 @@ TEST(SimpleParser, Gibberish) {
 
 // If Gibberish is in the middle, it should not parse.
 TEST(SimpleParser, GibberishInMiddle) {
-  SignatureParser::Table expectedTable{{1, 1}, {2, 3}};
   const auto table = SignatureParser::Parse("1/1 2/3 sdf 1/4");
   EXPECT(!table);
 }
 
+// A test with slash in the end
+TEST(SimpleParser, SlashInEnd) {
+  const auto table = SignatureParser::parse("1/1 2/");
+  EXPECT(!table);
+}
+
 /* ************************************************************************* */
 
 int main() {