diff --git a/re.c b/re.c
index bb6af74eb57f36..317790fba80e5e 100644
--- a/re.c
+++ b/re.c
@@ -3971,7 +3971,7 @@ static void
 set_timeout(rb_hrtime_t *hrt, VALUE timeout)
 {
     double timeout_d = NIL_P(timeout) ? 0.0 : NUM2DBL(timeout);
-    if (!NIL_P(timeout) && timeout_d <= 0) {
+    if (!NIL_P(timeout) && !(timeout_d > 0)) {
         rb_raise(rb_eArgError, "invalid timeout: %"PRIsVALUE, timeout);
     }
     double2hrtime(hrt, timeout_d);
diff --git a/scheduler.c b/scheduler.c
index 3205bb3bc9a7c3..7efd4274cb59a5 100644
--- a/scheduler.c
+++ b/scheduler.c
@@ -680,10 +680,14 @@ rb_fiber_scheduler_unblock(VALUE scheduler, VALUE blocker, VALUE fiber)
     int saved_interrupt_mask = ec->interrupt_mask;
     ec->interrupt_mask |= PENDING_INTERRUPT_MASK;
 
+    rb_control_frame_t *volatile cfp = ec->cfp;
     EC_PUSH_TAG(ec);
     if ((state = EC_EXEC_TAG()) == TAG_NONE) {
         result = rb_funcall(scheduler, id_unblock, 2, blocker, fiber);
     }
+    else {
+        rb_vm_rewind_cfp(ec, cfp);
+    }
     EC_POP_TAG();
 
     ec->interrupt_mask = saved_interrupt_mask;
@@ -1145,10 +1149,14 @@ VALUE rb_fiber_scheduler_fiber_interrupt(VALUE scheduler, VALUE fiber, VALUE exc
     int saved_interrupt_mask = ec->interrupt_mask;
     ec->interrupt_mask |= PENDING_INTERRUPT_MASK;
 
+    rb_control_frame_t *volatile cfp = ec->cfp;
     EC_PUSH_TAG(ec);
     if ((state = EC_EXEC_TAG()) == TAG_NONE) {
         result = rb_check_funcall(scheduler, id_fiber_interrupt, 2, arguments);
     }
+    else {
+        rb_vm_rewind_cfp(ec, cfp);
+    }
     EC_POP_TAG();
 
     ec->interrupt_mask = saved_interrupt_mask;
diff --git a/test/ruby/test_regexp.rb b/test/ruby/test_regexp.rb
index d545d983dc38b1..69e15bd4df687d 100644
--- a/test/ruby/test_regexp.rb
+++ b/test/ruby/test_regexp.rb
@@ -2035,6 +2035,7 @@ def test_s_timeout_corner_cases
       Regexp.timeout = 1e300
       assert_equal(((1<<64)-1) / 1000000000.0, Regexp.timeout)
 
+      assert_raise(ArgumentError) { Regexp.timeout = Float::NAN }
       assert_raise(ArgumentError) { Regexp.timeout = 0 }
       assert_raise(ArgumentError) { Regexp.timeout = -1 }
 
@@ -2127,6 +2128,7 @@ def test_timeout_corner_cases
 
       assert_equal(((1<<64)-1) / 1000000000.0, Regexp.new("foo", timeout: 1e300).timeout)
 
+      assert_raise(ArgumentError) { Regexp.new("foo", timeout: Float::NAN) }
       assert_raise(ArgumentError) { Regexp.new("foo", timeout: 0) }
       assert_raise(ArgumentError) { Regexp.new("foo", timeout: -1) }
     end;