diff --git a/src/Curta.sol b/src/Curta.sol
index 31a678d..e91537d 100644
--- a/src/Curta.sol
+++ b/src/Curta.sol
@@ -116,6 +116,9 @@ contract Curta is ICurta, FlagsERC721, Owned {
         // Revert if the puzzle does not exist.
         if (address(puzzle) == address(0)) revert PuzzleDoesNotExist(_puzzleId);
 
+        // Revert if puzzle name is an empty string or not implemented.
+        if (bytes(puzzle.name()).length == 0) revert PuzzleNotNamed(_puzzleId);
+
         // Revert if submissions are closed.
         uint40 firstSolveTimestamp = puzzleData.firstSolveTimestamp;
         uint40 solveTimestamp = uint40(block.timestamp);
diff --git a/src/interfaces/ICurta.sol b/src/interfaces/ICurta.sol
index 759ebed..6036d08 100644
--- a/src/interfaces/ICurta.sol
+++ b/src/interfaces/ICurta.sol
@@ -40,6 +40,10 @@ interface ICurta {
     /// @param _puzzleId The ID of a puzzle.
     error PuzzleDoesNotExist(uint32 _puzzleId);
 
+    /// @notice Emitted when a puzzle has a zero-length name.
+    /// @param _puzzleId The ID of a puzzle.
+    error PuzzleNotNamed(uint32 _puzzleId);
+
     /// @notice Emitted when the puzzle was not the one that went longest
     /// unsolved.
     /// @param _puzzleId The ID of a puzzle.