diff --git a/.gitattributes b/.gitattributes
index ae3656329c..d046c5e955 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -18348,6 +18348,7 @@ tests/webtbs/tw37228.pp svneol=native#text/plain
 tests/webtbs/tw37254.pp svneol=native#text/pascal
 tests/webtbs/tw37261.pp svneol=native#text/pascal
 tests/webtbs/tw37272a.pp svneol=native#text/pascal
+tests/webtbs/tw37301.pp svneol=native#text/pascal
 tests/webtbs/tw3742.pp svneol=native#text/plain
 tests/webtbs/tw3751.pp svneol=native#text/plain
 tests/webtbs/tw3758.pp svneol=native#text/plain
diff --git a/compiler/x86/aoptx86.pas b/compiler/x86/aoptx86.pas
index 063e72803f..7874a8db36 100644
--- a/compiler/x86/aoptx86.pas
+++ b/compiler/x86/aoptx86.pas
@@ -4322,14 +4322,14 @@ unit aoptx86;
                               with taicpu(hp4).oper[OperIdx]^ do
                                 case typ of
                                   top_reg:
-                                    if reg = NR_EDX then
-                                      reg := NR_EAX;
+                                    if getsupreg(reg) = RS_EDX then
+                                      reg := newreg(R_INTREGISTER,RS_EAX,getsubreg(reg));
                                   top_ref:
                                     begin
-                                      if ref^.base = NR_EDX then
-                                        ref^.base := NR_EAX;
-                                      if ref^.index = NR_EDX then
-                                        ref^.index := NR_EAX;
+                                      if getsupreg(reg) = RS_EDX then
+                                        ref^.base := newreg(R_INTREGISTER,RS_EAX,getsubreg(reg));
+                                      if getsupreg(reg) = RS_EDX then
+                                        ref^.index := newreg(R_INTREGISTER,RS_EAX,getsubreg(reg));
                                     end;
                                   else
                                     ;
diff --git a/tests/webtbs/tw37301.pp b/tests/webtbs/tw37301.pp
new file mode 100644
index 0000000000..43c20f939d
--- /dev/null
+++ b/tests/webtbs/tw37301.pp
@@ -0,0 +1,13 @@
+{ %OPT=-O- -O1 }
+program testbug;
+{$mode objfpc}{$h+}
+var
+  i: Integer;
+  b: Byte;
+  w: Word;
+begin
+  i := 53;
+  b := 0;
+  w := abs(i-b);
+  WriteLn(w);
+end.