diff --git a/tools/elf2efi.py b/tools/elf2efi.py
index a63d3fc98d..fff2b1a4be 100755
--- a/tools/elf2efi.py
+++ b/tools/elf2efi.py
@@ -611,7 +611,9 @@ def elf2efi(args: argparse.Namespace):
 
     coff.Machine = pe_arch
     coff.NumberOfSections = len(sections)
-    coff.TimeDateStamp = int(sde if (sde := os.environ.get("SOURCE_DATE_EPOCH")) else time.time())
+    coff.TimeDateStamp = int(
+        os.environ.get("SOURCE_DATE_EPOCH") if os.environ.get("SOURCE_DATE_EPOCH") else time.time()
+    )
     coff.SizeOfOptionalHeader = sizeof(opt)
     # EXECUTABLE_IMAGE|LINE_NUMS_STRIPPED|LOCAL_SYMS_STRIPPED|DEBUG_STRIPPED
     # and (32BIT_MACHINE or LARGE_ADDRESS_AWARE)