diff --git a/ebpfcat/ebpf.py b/ebpfcat/ebpf.py
index 4960a2e95c4bca9d0700e86d42bba23c6d7f39d8..84d2a878bec4ed6a711b501c52d059ebf30873d6 100644
--- a/ebpfcat/ebpf.py
+++ b/ebpfcat/ebpf.py
@@ -759,7 +759,7 @@ class PseudoFd(Expression):
         self.fd = fd
 
     @contextmanager
-    def calculate(self, dst, long, signed, force):
+    def calculate(self, dst, long, signed, force=False):
         with self.ebpf.get_free_register(dst) as dst:
             self.ebpf.append(Opcode.DW, dst, 1, 0, self.fd)
             self.ebpf.append(Opcode.W, 0, 0, 0, 0)
@@ -771,13 +771,13 @@ class ktime(Expression):
         self.ebpf = ebpf
 
     @contextmanager
-    def calculate(self, dst, long, signed, force):
+    def calculate(self, dst, long, signed, force=False):
         with self.ebpf.get_free_register(dst) as dst:
             with self.ebpf.save_registers([i for i in range(6) if i != dst]):
                 self.ebpf.call(FuncId.ktime_get_ns)
                 if dst != 0:
                     self.ebpf.r[dst] = self.ebpf.r0
-                yield dst, True, False
+            yield dst, True, False
 
 
 class RegisterDesc:
diff --git a/ebpfcat/ebpf_test.py b/ebpfcat/ebpf_test.py
index cba423606f02078c63475c42df1a71a6acda8733..8cea647e78f61b32b4ea4ee19c216e9ded462656 100644
--- a/ebpfcat/ebpf_test.py
+++ b/ebpfcat/ebpf_test.py
@@ -541,12 +541,17 @@ class Tests(TestCase):
 
     def test_ktime(self):
         e = EBPF()
+        e.r0 = 3
         e.r3 = ktime(e)
         self.assertEqual(e.opcodes, [
-            Instruction(opcode=O.REG+O.MOV+O.LONG, dst=6, src=1, off=0, imm=0),
+            Instruction(opcode=O.LONG+O.MOV, dst=0, src=0, off=0, imm=3),
+            Instruction(opcode=O.REG+O.MOV+O.LONG, dst=6, src=0, off=0, imm=0),
+            Instruction(opcode=O.REG+O.MOV+O.LONG, dst=7, src=1, off=0, imm=0),
             Instruction(opcode=O.CALL, dst=0, src=0, off=0, imm=5),
             Instruction(opcode=O.REG+O.MOV+O.LONG, dst=3, src=0, off=0, imm=0),
-            Instruction(opcode=O.REG+O.MOV+O.LONG, dst=1, src=6, off=0, imm=0)])
+            Instruction(opcode=O.REG+O.MOV+O.LONG, dst=0, src=6, off=0, imm=0),
+            Instruction(opcode=O.REG+O.MOV+O.LONG, dst=1, src=7, off=0, imm=0)
+            ])
 
     def test_xdp(self):
         e = XDP(license="GPL")