diff --git a/src/astgen.zig b/src/astgen.zig
index 93b6810259e8611747331c25e4f9746b044c5b32..6db25aab09fe86451290821502a8d3f43ca95579 100644
--- a/src/astgen.zig
+++ b/src/astgen.zig
@@ -33,6 +33,10 @@ pub const Block = struct {
 
     pub const Type = enum {
         each,
+        @"if",
+        ifnot,
+        ifequal,
+        ifnotequal,
     };
 };
 
diff --git a/src/lib.zig b/src/lib.zig
index a306db54d7864ff75ecda37d22bb025c7abd6893..34634599c6028de48f96ff0ed41aa2a059bccec3 100644
--- a/src/lib.zig
+++ b/src/lib.zig
@@ -91,6 +91,7 @@ fn do(writer: anytype, comptime value: astgen.Value, data: anytype, ctx: anytype
                         }
                     }
                 },
+                else => @compileError("pek: block: TODO " ++ @tagName(v.name)),
             }
         },
         else => unreachable,