diff --git a/.gitattributes b/.gitattributes
index d93a4532a6..b1c811b585 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -18471,6 +18471,7 @@ tests/webtbs/tw3768.pp svneol=native#text/plain
 tests/webtbs/tw3774.pp svneol=native#text/plain
 tests/webtbs/tw3777.pp svneol=native#text/plain
 tests/webtbs/tw3778.pp svneol=native#text/plain
+tests/webtbs/tw37780.pp svneol=native#text/plain
 tests/webtbs/tw3780.pp svneol=native#text/plain
 tests/webtbs/tw3782.pp svneol=native#text/plain
 tests/webtbs/tw3796.pp svneol=native#text/plain
diff --git a/compiler/nadd.pas b/compiler/nadd.pas
index 0bac5e4322..5b36920c92 100644
--- a/compiler/nadd.pas
+++ b/compiler/nadd.pas
@@ -1348,7 +1348,7 @@ implementation
                    (left.nodetype=equaln) and
                    (right.nodetype=equaln) and
                    (not might_have_sideeffects(left)) and
-                   (not might_have_sideeffects(right)) and
+                   (not might_have_sideeffects(right,[mhs_exceptions])) and
                    (is_constintnode(taddnode(left).left) or is_constintnode(taddnode(left).right) or
                     is_constpointernode(taddnode(left).left) or is_constpointernode(taddnode(left).right) or
                     is_constcharnode(taddnode(left).left) or is_constcharnode(taddnode(left).right)) and
diff --git a/tests/webtbs/tw37780.pp b/tests/webtbs/tw37780.pp
new file mode 100644
index 0000000000..2cdb66496e
--- /dev/null
+++ b/tests/webtbs/tw37780.pp
@@ -0,0 +1,18 @@
+program testbug;
+
+type
+  PTestRec = ^TTestRec;
+  TTestRec = record
+    Val: Integer;
+    Next: PTestRec;
+  end;
+
+var
+  TR: TTestRec;
+
+begin
+  TR.Val := 6;
+  TR.Next := nil;
+  if (TR.Val = 10) or ((TR.Val = 5) and (TR.Next^.Val = 5)) then
+    Writeln('OK');
+end.