diff --git a/runtime/lua/man.lua b/runtime/lua/man.lua
index 732a4ab92e..0956022ac6 100644
--- a/runtime/lua/man.lua
+++ b/runtime/lua/man.lua
@@ -149,15 +149,21 @@ local function highlight_line(line, linenr)
     if overstrike then
       local last_hl = hls[#hls]
       if char == prev_char then
-        if char == '_' and attr == UNDERLINE and last_hl and last_hl.final == byte then
-          -- This underscore is in the middle of an underlined word
-          attr = UNDERLINE
+        if char == '_' and attr == ITALIC and last_hl and last_hl.final == byte then
+          -- This underscore is in the middle of an italic word
+          attr = ITALIC
         else
           attr = BOLD
         end
       elseif prev_char == '_' then
-        -- char is underlined
-        attr = UNDERLINE
+        -- Even though underline is strictly what this should be. <bs>_ was used by nroff to
+        -- indicate italics which wasn't possible on old typewriters so underline was used. Modern
+        -- terminals now support italics so lets use that now.
+        -- See:
+        -- - https://unix.stackexchange.com/questions/274658/purpose-of-ascii-text-with-overstriking-file-format/274795#274795
+        -- - https://cmd.inp.nsk.su/old/cmd2/manuals/unix/UNIX_Unleashed/ch08.htm
+        -- attr = UNDERLINE
+        attr = ITALIC
       elseif prev_char == '+' and char == 'o' then
         -- bullet (overstrike text '+^Ho')
         attr = BOLD
diff --git a/test/functional/plugin/man_spec.lua b/test/functional/plugin/man_spec.lua
index c6c7d2b03d..58da059be6 100644
--- a/test/functional/plugin/man_spec.lua
+++ b/test/functional/plugin/man_spec.lua
@@ -59,7 +59,7 @@ describe(':Man', function()
 
       screen:expect([[
       ^this {b:is} {b:a} test                                      |
-      with {u:overstruck} text                                |
+      with {i:overstruck} text                                |
       {eob:~                                                   }|
       {eob:~                                                   }|
                                                           |
@@ -98,7 +98,7 @@ describe(':Man', function()
 
       screen:expect([[
       ^this {b:is} {b:あ} test                                     |
-      with {u:överstrũck} te{i:xt¶}                               |
+      with {i:överstrũck} te{i:xt¶}                               |
       {eob:~                                                   }|
       {eob:~                                                   }|
                                                           |
@@ -115,7 +115,7 @@ describe(':Man', function()
       screen:expect([[
       {b:^_begins}                                             |
       {b:mid_dle}                                             |
-      {u:mid_dle}                                             |
+      {i:mid_dle}                                             |
       {eob:~                                                   }|
                                                           |
       ]])