diff --git a/include/overlay005/const_ov5_021F89B0.h b/include/overlay005/const_ov5_021F89B0.h
deleted file mode 100644
index 0ebd94efed..0000000000
--- a/include/overlay005/const_ov5_021F89B0.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef POKEPLATINUM_CONST_OV5_021F89B0_H
-#define POKEPLATINUM_CONST_OV5_021F89B0_H
-
-#include "overlay_manager.h"
-
-extern const OverlayManagerTemplate gFieldMapTemplate;
-
-#endif // POKEPLATINUM_CONST_OV5_021F89B0_H
diff --git a/include/overlay005/ov5_021D0D80.h b/include/overlay005/fieldmap.h
similarity index 84%
rename from include/overlay005/ov5_021D0D80.h
rename to include/overlay005/fieldmap.h
index 0fd3afbba8..c11a886820 100644
--- a/include/overlay005/ov5_021D0D80.h
+++ b/include/overlay005/fieldmap.h
@@ -4,6 +4,9 @@
 #include "field/field_system_decl.h"
 
 #include "bg_window.h"
+#include "overlay_manager.h"
+
+extern const OverlayManagerTemplate gFieldMapTemplate;
 
 void ov5_021D12D0(FieldSystem *fieldSystem, u32 param1);
 void ov5_021D1434(BgConfig *param0);
diff --git a/src/field_menu.c b/src/field_menu.c
index f27b3aa99d..ed78328343 100644
--- a/src/field_menu.c
+++ b/src/field_menu.c
@@ -28,7 +28,7 @@
 #include "functypes/funcptr_0203BC5C.h"
 #include "functypes/funcptr_02050904.h"
 #include "gmm/message_bank_unk_0367.h"
-#include "overlay005/ov5_021D0D80.h"
+#include "overlay005/fieldmap.h"
 #include "overlay005/ov5_021D2F14.h"
 #include "overlay005/save_info_window.h"
 #include "overlay021/struct_ov21_021D0D80.h"
diff --git a/src/field_system.c b/src/field_system.c
index ca7b9cf836..1a5f993c53 100644
--- a/src/field_system.c
+++ b/src/field_system.c
@@ -8,8 +8,8 @@
 #include "consts/map.h"
 
 #include "field/field_system_sub2_t.h"
-#include "overlay005/const_ov5_021F89B0.h"
 #include "overlay005/field_control.h"
+#include "overlay005/fieldmap.h"
 #include "overlay005/ov5_021DD6FC.h"
 #include "overlay005/ov5_021DFB54.h"
 #include "overlay005/ov5_021E1B08.h"
diff --git a/src/overlay005/encounter_effect.c b/src/overlay005/encounter_effect.c
index 606c59128d..d4073e8d94 100644
--- a/src/overlay005/encounter_effect.c
+++ b/src/overlay005/encounter_effect.c
@@ -14,10 +14,10 @@
 #include "field/field_system_sub2_t.h"
 #include "overlay005/encounter_effect.h"
 #include "overlay005/encounter_effect_core.h"
+#include "overlay005/fieldmap.h"
 #include "overlay005/hblank_system.h"
 #include "overlay005/linear_interpolation_task_fx32.h"
 #include "overlay005/linear_interpolation_task_s32.h"
-#include "overlay005/ov5_021D0D80.h"
 #include "overlay005/quadratic_interpolation_task_fx32.h"
 #include "overlay005/struct_ov5_021DDF24.h"
 #include "overlay005/struct_ov5_021DE47C.h"
diff --git a/src/overlay005/fieldmap.c b/src/overlay005/fieldmap.c
index fe68e63205..d69295d9a4 100644
--- a/src/overlay005/fieldmap.c
+++ b/src/overlay005/fieldmap.c
@@ -1,3 +1,5 @@
+#include "overlay005/fieldmap.h"
+
 #include <nitro.h>
 #include <string.h>
 
@@ -12,12 +14,10 @@
 #include "field/field_system.h"
 #include "field/field_system_sub2_decl.h"
 #include "field/field_system_sub2_t.h"
-#include "overlay005/const_ov5_021F89B0.h"
 #include "overlay005/const_ov5_021FF6B8.h"
 #include "overlay005/const_ov5_021FF744.h"
 #include "overlay005/const_ov5_021FF7D0.h"
 #include "overlay005/hblank_system.h"
-#include "overlay005/ov5_021D0D80.h"
 #include "overlay005/ov5_021D1A94.h"
 #include "overlay005/ov5_021D37AC.h"
 #include "overlay005/ov5_021D521C.h"
@@ -117,7 +117,7 @@ static BOOL FieldMap_Exit(OverlayManager *overlayMan, int *param1);
 static BOOL FieldMap_ChangeZone(FieldSystem *fieldSystem);
 static void ov5_021D134C(FieldSystem *fieldSystem, u8 param1);
 static BOOL ov5_021D119C(FieldSystem *fieldSystem);
-static void ov5_021D0D80(void *param0);
+static void fieldmap(void *param0);
 static void ov5_021D13B4(FieldSystem *fieldSystem);
 static int ov5_021D1178(FieldSystem *fieldSystem);
 static BOOL FieldMap_InDistortionWorld(FieldSystem *fieldSystem);
@@ -126,7 +126,7 @@ static const int *ov5_021D1A68(const UnkStruct_ov5_021D1A68 *param0);
 static const int ov5_021D1A6C(const UnkStruct_ov5_021D1A68 *param0);
 static void ov5_021D1A70(UnkStruct_ov5_021D1A68 *param0);
 
-static inline void inline_ov5_021D0D80(FieldSystem *fieldSystem)
+static inline void inline_fieldmap(FieldSystem *fieldSystem)
 {
     UnkStruct_ov5_021ED0A4 *v0 = sub_0206285C(fieldSystem->mapObjMan);
     UnkStruct_02020C44 *v1 = ov5_021EDC8C(v0);
@@ -134,7 +134,7 @@ static inline void inline_ov5_021D0D80(FieldSystem *fieldSystem)
     sub_02020D68(v1);
 }
 
-static void ov5_021D0D80(void *param0)
+static void fieldmap(void *param0)
 {
     FieldSystem *fieldSystem = param0;
 
@@ -142,7 +142,7 @@ static void ov5_021D0D80(void *param0)
     sub_0201DCAC();
     sub_0200A858();
 
-    inline_ov5_021D0D80(fieldSystem);
+    inline_fieldmap(fieldSystem);
 }
 
 static BOOL FieldMap_Init(OverlayManager *overlayMan, int *param1)
@@ -929,7 +929,7 @@ static void ov5_021D1968(FieldSystem *fieldSystem)
     ov5_021D5CE4(fieldSystem->unk_04->unk_10, ov5_021EFA8C(fieldSystem->unk_30));
     sub_02068344(fieldSystem);
     ov5_021EE7C0(fieldSystem);
-    SetMainCallback(ov5_021D0D80, fieldSystem);
+    SetMainCallback(fieldmap, fieldSystem);
 }
 
 static UnkStruct_ov5_021D1A68 *ov5_021D1A14(int fieldSystem, int param1)
diff --git a/src/overlay005/ov5_021D431C.c b/src/overlay005/ov5_021D431C.c
index f8f5eb3afe..b733ea5673 100644
--- a/src/overlay005/ov5_021D431C.c
+++ b/src/overlay005/ov5_021D431C.c
@@ -8,7 +8,7 @@
 #include "struct_defs/struct_02055130.h"
 
 #include "field/field_system.h"
-#include "overlay005/ov5_021D0D80.h"
+#include "overlay005/fieldmap.h"
 #include "overlay005/ov5_021D37AC.h"
 #include "overlay005/ov5_021E15F4.h"
 #include "overlay005/ov5_021EF75C.h"
diff --git a/src/overlay006/ov6_0223E140.c b/src/overlay006/ov6_0223E140.c
index 41422753f1..0b836f367b 100644
--- a/src/overlay006/ov6_0223E140.c
+++ b/src/overlay006/ov6_0223E140.c
@@ -10,8 +10,8 @@
 
 #include "field/field_system.h"
 #include "field/field_system_sub2_t.h"
+#include "overlay005/fieldmap.h"
 #include "overlay005/motion_blur.h"
-#include "overlay005/ov5_021D0D80.h"
 #include "overlay005/ov5_021D1A94.h"
 #include "overlay005/ov5_021D521C.h"
 #include "overlay005/struct_ov5_021D1BEC_decl.h"
diff --git a/src/overlay007/ov7_0224CD28.c b/src/overlay007/ov7_0224CD28.c
index f083f78305..4903036a0c 100644
--- a/src/overlay007/ov7_0224CD28.c
+++ b/src/overlay007/ov7_0224CD28.c
@@ -8,7 +8,7 @@
 #include "struct_decls/struct_020508D4_decl.h"
 
 #include "field/field_system.h"
-#include "overlay005/ov5_021D0D80.h"
+#include "overlay005/fieldmap.h"
 #include "overlay005/ov5_021D2F14.h"
 #include "overlay007/struct_ov7_0224D008.h"
 #include "overlay007/struct_ov7_0224F2EC.h"
diff --git a/src/overlay009/ov9_02249960.c b/src/overlay009/ov9_02249960.c
index c3d45aae83..0f6b7e7a18 100644
--- a/src/overlay009/ov9_02249960.c
+++ b/src/overlay009/ov9_02249960.c
@@ -18,8 +18,8 @@
 
 #include "field/field_system.h"
 #include "field/field_system_sub2_t.h"
+#include "overlay005/fieldmap.h"
 #include "overlay005/map_object_anim_cmd.h"
-#include "overlay005/ov5_021D0D80.h"
 #include "overlay005/ov5_021D57BC.h"
 #include "overlay005/ov5_021DF440.h"
 #include "overlay005/ov5_021E779C.h"
diff --git a/src/unk_02056B30.c b/src/unk_02056B30.c
index cd3d5be2cf..78c36b8ade 100644
--- a/src/unk_02056B30.c
+++ b/src/unk_02056B30.c
@@ -11,8 +11,8 @@
 #include "field/field_system_sub2_t.h"
 #include "functypes/funcptr_020EC560.h"
 #include "functypes/funcptr_020EC57C.h"
+#include "overlay005/fieldmap.h"
 #include "overlay005/hblank_system.h"
-#include "overlay005/ov5_021D0D80.h"
 #include "overlay005/ov5_021D431C.h"
 #include "overlay005/ov5_021DD6FC.h"
 #include "overlay005/struct_ov5_021D432C_decl.h"
diff --git a/src/unk_0205A0D8.c b/src/unk_0205A0D8.c
index 94e5d5e98d..1fbcfb3f60 100644
--- a/src/unk_0205A0D8.c
+++ b/src/unk_0205A0D8.c
@@ -11,7 +11,7 @@
 
 #include "field/field_system.h"
 #include "functypes/funcptr_0205AB10.h"
-#include "overlay005/ov5_021D0D80.h"
+#include "overlay005/fieldmap.h"
 
 #include "bag.h"
 #include "bg_window.h"
diff --git a/src/unk_020683F4.c b/src/unk_020683F4.c
index edc2b71924..80d9b05a54 100644
--- a/src/unk_020683F4.c
+++ b/src/unk_020683F4.c
@@ -15,7 +15,7 @@
 #include "field/field_system.h"
 #include "functypes/funcptr_0203BC5C.h"
 #include "functypes/funcptr_02069238.h"
-#include "overlay005/ov5_021D0D80.h"
+#include "overlay005/fieldmap.h"
 #include "overlay005/ov5_021DFB54.h"
 #include "overlay005/ov5_021F007C.h"
 #include "overlay005/ov5_021F08CC.h"
diff --git a/src/unk_020985E4.c b/src/unk_020985E4.c
index 3a8f8815b7..4fdb59ce7f 100644
--- a/src/unk_020985E4.c
+++ b/src/unk_020985E4.c
@@ -8,7 +8,7 @@
 #include "struct_defs/struct_0209862C.h"
 
 #include "field/field_system.h"
-#include "overlay005/ov5_021D0D80.h"
+#include "overlay005/fieldmap.h"
 #include "overlay100/ov100_021D0D80.h"
 
 #include "field_system.h"
diff --git a/src/unk_0209AC14.c b/src/unk_0209AC14.c
index dbf38b8cf5..ff88d50ed8 100644
--- a/src/unk_0209AC14.c
+++ b/src/unk_0209AC14.c
@@ -6,7 +6,7 @@
 #include "struct_decls/struct_020508D4_decl.h"
 
 #include "field/field_system.h"
-#include "overlay005/ov5_021D0D80.h"
+#include "overlay005/fieldmap.h"
 #include "overlay007/ov7_0224CD28.h"
 #include "overlay007/struct_ov7_0224D008.h"
 
diff --git a/src/unk_0209ACF4.c b/src/unk_0209ACF4.c
index 97446c8da7..c4402c05ce 100644
--- a/src/unk_0209ACF4.c
+++ b/src/unk_0209ACF4.c
@@ -8,7 +8,7 @@
 #include "struct_defs/sentence.h"
 
 #include "field/field_system.h"
-#include "overlay005/ov5_021D0D80.h"
+#include "overlay005/fieldmap.h"
 
 #include "bg_window.h"
 #include "colored_arrow.h"
diff --git a/src/unk_0209B344.c b/src/unk_0209B344.c
index 0a169720b4..6445c247dc 100644
--- a/src/unk_0209B344.c
+++ b/src/unk_0209B344.c
@@ -8,7 +8,7 @@
 #include "struct_defs/sentence.h"
 
 #include "field/field_system.h"
-#include "overlay005/ov5_021D0D80.h"
+#include "overlay005/fieldmap.h"
 
 #include "heap.h"
 #include "savedata_misc.h"