diff --git a/src/puya/awst/nodes.py b/src/puya/awst/nodes.py
index e3a4527c5a..5b6c66dc91 100644
--- a/src/puya/awst/nodes.py
+++ b/src/puya/awst/nodes.py
@@ -692,6 +692,7 @@ class TxnFields:
     TxnFields.approval_program_pages,
     TxnFields.clear_state_program_pages,
 ]
+TXN_FIELDS_BY_IMMEDIATE = {f.immediate: f for f in TXN_FIELDS}
 INNER_PARAM_TXN_FIELDS = [f for f in TXN_FIELDS if f.is_inner_param]
 
 
diff --git a/src/puya/awst_build/eb/arc4/abi_call.py b/src/puya/awst_build/eb/arc4/abi_call.py
index 1a3468b103..f10174f177 100644
--- a/src/puya/awst_build/eb/arc4/abi_call.py
+++ b/src/puya/awst_build/eb/arc4/abi_call.py
@@ -11,7 +11,7 @@
 from puya import log
 from puya.awst import wtypes
 from puya.awst.nodes import (
-    TXN_FIELDS,
+    TXN_FIELDS_BY_IMMEDIATE,
     ARC4Decode,
     BytesConstant,
     BytesEncoding,
@@ -58,23 +58,24 @@
 
 logger = log.get_logger(__name__)
 _APP_TRANSACTION_FIELDS = {
-    get_field_python_name(f): f
-    for f in TXN_FIELDS
-    if f.immediate
-    in (
-        "ApplicationID",
-        "OnCompletion",
-        "ApprovalProgram",
-        "ClearStateProgram",
-        "GlobalNumUInt",
-        "GlobalNumByteSlice",
-        "LocalNumUInt",
-        "LocalNumByteSlice",
-        "ExtraProgramPages",
-        "Fee",
-        "Sender",
-        "Note",
-        "RekeyTo",
+    get_field_python_name(field): field
+    for field in (
+        TXN_FIELDS_BY_IMMEDIATE[immediate]
+        for immediate in (
+            "ApplicationID",
+            "OnCompletion",
+            "ApprovalProgram",
+            "ClearStateProgram",
+            "GlobalNumUint",
+            "GlobalNumByteSlice",
+            "LocalNumUint",
+            "LocalNumByteSlice",
+            "ExtraProgramPages",
+            "Fee",
+            "Sender",
+            "Note",
+            "RekeyTo",
+        )
     )
 }