diff --git a/unified/ql/lib/codeql/unified/internal/AstExtra.qll b/unified/ql/lib/codeql/unified/internal/AstExtra.qll
index 378712b86cb9..f5a9ad09caaa 100644
--- a/unified/ql/lib/codeql/unified/internal/AstExtra.qll
+++ b/unified/ql/lib/codeql/unified/internal/AstExtra.qll
@@ -5,13 +5,24 @@
 private import unified
 
 module Public {
-  /**
-   * A logical 'and' expression with short-circuiting.
-   */
+  /** A short-circuiting logical AND expression. */
   class LogicalAndExpr extends BinaryExpr {
     LogicalAndExpr() { this.getOperator().getValue() = "&&" }
+  }
+
+  /** A short-circuiting logical OR expression. */
+  class LogicalOrExpr extends BinaryExpr {
+    LogicalOrExpr() { this.getOperator().getValue() = "||" }
+  }
+
+  /** A short-circuiting null-coalescing expression. */
+  class NullCoalescingExpr extends BinaryExpr {
+    NullCoalescingExpr() { this.getOperator().getValue() = "??" }
+  }
 
-    Expr getAnOperand() { result = [this.getLeft(), this.getRight()] }
+  /** A logical NOT expression. */
+  class LogicalNotExpr extends UnaryExpr {
+    LogicalNotExpr() { this.getOperator().(PrefixOperator).getValue() = "!" }
   }
 
   /**
diff --git a/unified/ql/lib/codeql/unified/internal/FacadeAst.qll b/unified/ql/lib/codeql/unified/internal/FacadeAst.qll
index 44adef76e425..af66648a345c 100644
--- a/unified/ql/lib/codeql/unified/internal/FacadeAst.qll
+++ b/unified/ql/lib/codeql/unified/internal/FacadeAst.qll
@@ -49,6 +49,12 @@ module Unified {
     }
   }
 
+  /** A binary expression. */
+  class BinaryExpr extends G::BinaryExpr {
+    /** Gets an operand of this binary expression. */
+    Expr getAnOperand() { result = [this.getLeft(), this.getRight()] }
+  }
+
   /** A function call */
   class CallExpr extends G::CallExpr {
     /** Gets the named argument with the given `name`. */