diff --git a/src/display.c b/src/display.c
index b98fc88c8..31c92d14c 100644
--- a/src/display.c
+++ b/src/display.c
@@ -2309,7 +2309,10 @@ glyphinfo_at(coordxy x, coordxy y, int glyph)
  */
 
 static void
-get_bkglyph_and_framecolor(coordxy x, coordxy y, int *bkglyph, uint32 *framecolor)
+get_bkglyph_and_framecolor(
+    coordxy x, coordxy y,
+    int *bkglyph,
+    uint32 *framecolor)
 {
     int idx, tmp_bkglyph = GLYPH_UNEXPLORED;
     struct rm *lev = &levl[x][y];
@@ -3179,7 +3182,8 @@ const seenV seenv_matrix[3][3] = {
     { SV4, SV5,   SV6 }
 };
 
-#define sign(z) ((z) < 0 ? -1 : ((z) > 0 ? 1 : 0))
+/* negative: -1, zero: 0, positive +1; same as sgn() function (hacklib.c) */
+#define sign(z) ((z) < 0 ? -1 : ((z) != 0))
 
 /* Set the seen vector of lev as if seen from (x0,y0) to (x,y). */
 static void
@@ -3193,6 +3197,8 @@ set_seenv(
     lev->seenv |= seenv_matrix[sign(dy) + 1][sign(dx) + 1];
 }
 
+#undef sign
+
 /* Called by blackout(vault.c) when vault guard removes temporary corridor,
    turning spot <x0,y0> back into stone; <x1,y1> is an adjacent spot. */
 void
@@ -3640,4 +3646,20 @@ fn_cmap_to_glyph(int cmap)
 {
     return cmap_to_glyph(cmap);
 }
+
+/* for 'onefile' processing where end of this file isn't necessarily the
+   end of the source code seen by the compiler (there are lots of other
+   macros defined above...) */
+#undef remember_topology
+#undef DETECTED
+#undef PHYSICALLY_SEEN
+#undef is_worm_tail
+#undef TMP_AT_MAX_GLYPHS
+#undef Glyphinfo_at
+#undef reset_glyph_bbox
+#undef HAS_ROGUE_IBM_GRAPHICS
+#undef HI_DOMESTIC
+#undef GMAP_SET
+#undef GMAP_ROGUELEVEL
+
 /*display.c*/
diff --git a/src/insight.c b/src/insight.c
index cb35b8c6e..ef00fca02 100644
--- a/src/insight.c
+++ b/src/insight.c
@@ -3222,4 +3222,14 @@ ustatusline(void)
           Upolyd ? u.mhmax : u.uhpmax, u.uac, info);
 }
 
+/* for 'onefile' processing where end of this file isn't necessarily the
+   end of the source code seen by the compiler */
+#undef enl_msg
+#undef you_are
+#undef you_have
+#undef you_can
+#undef you_have_been
+#undef you_have_never
+#undef you_have_X
+
 /*insight.c*/
diff --git a/src/light.c b/src/light.c
index b37a2cd40..e09073516 100644
--- a/src/light.c
+++ b/src/light.c
@@ -871,4 +871,10 @@ wiz_light_sources(void)
     return ECMD_OK;
 }
 
+/* for 'onefile' processing where end of this file isn't necessarily the
+   end of the source code seen by the compiler */
+#undef LSF_SHOW
+#undef LSF_NEEDS_FIXUP
+#undef mon_is_local
+
 /*light.c*/
diff --git a/src/monst.c b/src/monst.c
index 2ac7f0781..04c80bd8b 100644
--- a/src/monst.c
+++ b/src/monst.c
@@ -28,16 +28,18 @@
 #define WT_ELF 800
 #define WT_DRAGON 4500
 
-#define MON(nam, sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, col, bn) \
-    {                                                                      \
-        {(const char *) 0, (const char *) 0, nam}, \
-        sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, C(col)   \
+#define MON(nam, sym, lvl, gen, atk, siz, mr1, mr2, \
+            flg1, flg2, flg3, d, col, bn)           \
+    {                                                                       \
+        { (const char *) 0, (const char *) 0, nam },                        \
+            sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, C(col)  \
     }
 
-#define MON3(namm, namf, namn, sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, col, bn) \
-    {                                                                      \
-        {namm, namf, namn}, \
-        sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, C(col)   \
+#define MON3(namm, namf, namn, sym, lvl, gen, atk, siz, mr1, mr2, \
+             flg1, flg2, flg3, d, col, bn)                        \
+    {                                                                       \
+        { namm, namf, namn },                                               \
+        sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, C(col)      \
     }
 /* LVL() and SIZ() collect several fields to cut down on number of args
  * for MON()
@@ -71,11 +73,29 @@ struct permonst mons[SIZE(mons_init)];
 void
 monst_globals_init(void)
 {
-    memcpy(mons, mons_init, sizeof(mons));
+    memcpy(mons, mons_init, sizeof mons);
     return;
 }
 
 const struct attack c_sa_yes[NATTK] = SEDUCTION_ATTACKS_YES;
 const struct attack c_sa_no[NATTK] = SEDUCTION_ATTACKS_NO;
 
+/* for 'onefile' processing where end of this file isn't necessarily the
+   end of the source code seen by the compiler */
+#undef C
+#define C(c) (0x1f & (c)) /* global.h */
+#ifdef TEXTCOLOR
+#undef HI_DOMESTIC
+#undef HI_LORD
+#endif
+#undef NO_ATTK
+#undef WT_ELF
+#undef WT_DRAGON
+#undef MON
+#undef MON3
+#undef LVL
+#undef SIZ
+#undef ATTK
+#undef A
+
 /*monst.c*/
diff --git a/src/nhlobj.c b/src/nhlobj.c
index 584a8f4a1..ef8303528 100644
--- a/src/nhlobj.c
+++ b/src/nhlobj.c
@@ -655,3 +655,8 @@ l_obj_register(lua_State *L)
     return 0;
 }
 
+/* for 'onefile' processing where end of this file isn't necessarily the
+   end of the source code seen by the compiler */
+#undef lobj_is_ok
+
+/*nhlobj.c*/