diff --git a/src/infrastructure/markup/blockrule/PhutilRemarkupCodeBlockRule.php b/src/infrastructure/markup/blockrule/PhutilRemarkupCodeBlockRule.php
--- a/src/infrastructure/markup/blockrule/PhutilRemarkupCodeBlockRule.php
+++ b/src/infrastructure/markup/blockrule/PhutilRemarkupCodeBlockRule.php
@@ -44,11 +44,18 @@
   }
 
   public function markupText($text, $children) {
-    if (preg_match('/^\s*```/', $text)) {
+    $very_first_line = null;
+    if (preg_match('/^\s*```(.*)/', $text, $matches)) {
       // If this is a ```-style block, trim off the backticks and any leading
       // blank line.
       $text = preg_replace('/^\s*```(\s*\n)?/', '', $text);
       $text = preg_replace('/```\s*$/', '', $text);
+
+      // Just after the opening backticks there can be something valuable.
+      // Note that the general options are not necessarily here.
+      if (isset($matches[1])) {
+        $very_first_line = $matches[1];
+      }
     }
 
     $lines = explode("\n", $text);
@@ -79,6 +86,17 @@
       }
     }
 
+    // If explicitly missing, eventually parse the language expressed
+    // just after the first backticks.
+    // Skip one-line blocks, to do not eat potential one-line content.
+    // If found, we remove that line since it is not content.
+    if (empty($options['lang']) && $very_first_line && count($lines) > 1) {
+      if (preg_match('/^[a-z0-9\-\+\#\/]+$/', $very_first_line)) {
+        $options['lang'] = $very_first_line;
+        array_shift($lines);
+      }
+    }
+
     // Normalize the text back to a 0-level indent.
     $min_indent = 80;
     foreach ($lines as $line) {