diff --git a/source/build/src/sdlayer12.cpp b/source/build/src/sdlayer12.cpp
index e0789387a..b70d68c7a 100644
--- a/source/build/src/sdlayer12.cpp
+++ b/source/build/src/sdlayer12.cpp
@@ -559,6 +559,7 @@ int32_t handleevents_pollsdl(void)
                     ev.motion.yrel /= 12;
                 }
 #endif
+            fallthrough__;
             default: // OSD_Printf("Got event (%d)\n", ev.type); break;
                 rv = handleevents_sdlcommon(&ev);
                 break;
diff --git a/source/duke3d/src/actors.cpp b/source/duke3d/src/actors.cpp
index 4a800f569..e58564c3a 100644
--- a/source/duke3d/src/actors.cpp
+++ b/source/duke3d/src/actors.cpp
@@ -4637,7 +4637,7 @@ ACTOR_STATIC void G_MoveActors(void)
             int const j        = A_Spawn(spriteNum, (PLUTOPAK ? FRAMEEFFECT1 : FRAMEEFFECT1_13));
             actor[j].t_data[0] = 3;
         }
-        /* fall-through */
+            fallthrough__;
         case HEAVYHBOMB__STATIC:
         {
             int           playerNum;
@@ -7347,11 +7347,11 @@ ACTOR_STATIC void G_MoveEffectors(void)   //STATNUM 3
 
                             case LASERLINE__STATIC: continue;
                         }
-                    // fall-through
+                        fallthrough__;
                     case STAT_STANDABLE:
                         if (sprite[sectSprite].picnum == TRIPBOMB)
                             break;
-                    // else, fall-through
+                        fallthrough__;
                     case STAT_ACTOR:
                     case STAT_DEFAULT:
                         if (sprite[sectSprite].picnum == BOLT1
diff --git a/source/duke3d/src/astub.cpp b/source/duke3d/src/astub.cpp
index 830e1d25a..f044891d4 100644
--- a/source/duke3d/src/astub.cpp
+++ b/source/duke3d/src/astub.cpp
@@ -7683,7 +7683,7 @@ static void Keys2d(void)
                 {
                 case 0:
                     printmessage16("MAP LIMITS EXCEEDED!");
-                    /* fall-through */
+                    fallthrough__;
                 default:
                     k = 0;
                     break;
diff --git a/source/duke3d/src/game.cpp b/source/duke3d/src/game.cpp
index 44835b5c4..598f913df 100644
--- a/source/duke3d/src/game.cpp
+++ b/source/duke3d/src/game.cpp
@@ -3174,7 +3174,7 @@ int A_Spawn(int spriteNum, int tileNum)
 
             case SE_11_SWINGING_DOOR:  // Pivitor rotater
                 T4(newSprite) = (pSprite->ang > 1024) ? 2 : -2;
-            /* fall-through */
+                fallthrough__;
             case SE_0_ROTATING_SECTOR:
             case SE_2_EARTHQUAKE:      // Earthquakemakers
             case SE_5:                 // Boss Creature
diff --git a/source/duke3d/src/m32def.cpp b/source/duke3d/src/m32def.cpp
index 0ed1c4575..27ff845c8 100644
--- a/source/duke3d/src/m32def.cpp
+++ b/source/duke3d/src/m32def.cpp
@@ -2027,7 +2027,7 @@ static int32_t C_ParseCommand(void)
             *g_scriptPtr++ = -1;
             return 0;
         }
-        // fall-through
+        fallthrough__;
     case CON_STATE:
         if (C_GetNextLabelName(1))
             return 1;
@@ -2622,7 +2622,7 @@ repeatcase:
             return 1;
         }
         textptr++;
-        // fall-through
+        fallthrough__;
     case CON_SETARRAY:
         if (C_GetNextLabelName(1))
             return 1;
diff --git a/source/duke3d/src/player.cpp b/source/duke3d/src/player.cpp
index 92f472c58..a79dc4c2d 100644
--- a/source/duke3d/src/player.cpp
+++ b/source/duke3d/src/player.cpp
@@ -1109,7 +1109,7 @@ static int32_t A_ShootHardcoded(int spriteNum, int projecTile, int shootAng, vec
             if (playerNum < 0)
                 shootAng += 1024;
             Zvel = 1024 - (krand() & 2047);
-        // fall-through
+            fallthrough__;
         case KNEE__STATIC:
             if (projecTile == KNEE)
             {
diff --git a/source/duke3d/src/sector.cpp b/source/duke3d/src/sector.cpp
index 0700a6d83..3b7086c62 100644
--- a/source/duke3d/src/sector.cpp
+++ b/source/duke3d/src/sector.cpp
@@ -1389,7 +1389,7 @@ int P_ActivateSwitch(int playerNum, int wallOrSprite, int switchType)
         default:
             if (CheckDoorTile(nSwitchPicnum) == 0)
                 break;
-        /* fall-through */
+            fallthrough__;
         case DIPSWITCH_LIKE_CASES:
             if (G_IsLikeDipswitch(nSwitchPicnum))
             {
@@ -1401,7 +1401,7 @@ int P_ActivateSwitch(int playerNum, int wallOrSprite, int switchType)
 
                 S_PlaySound3D(END_OF_LEVEL_WARN, g_player[playerNum].ps->i, &davector);
             }
-        /* fall-through */
+            fallthrough__;
         case ACCESSSWITCH_CASES:
         case MULTISWITCH__STATIC:
         case REST_SWITCH_CASES:
@@ -1563,7 +1563,7 @@ void A_DamageWall_Internal(int spriteNum, int wallNum, const vec3_t *vPos, int w
 #ifndef EDUKE32_STANDALONE
             case W_FORCEFIELD__STATIC:
                 pWall->extra = 1;  // tell the forces to animate
-            /* fall-through */
+                fallthrough__;
             case BIGFORCE__STATIC:
             {
                 updatesector(vPos->x, vPos->y, &sectNum);
@@ -2116,7 +2116,7 @@ void A_DamageObject_Internal(int spriteNum, int const dmgSrc)
         }
         A_PlaySound(GLASS_HEAVYBREAK,spriteNum);
         A_PlaySound(SQUISHED,spriteNum);
-        /* fall-through */
+        fallthrough__;
     case BOTTLE7__STATIC:
         A_PlaySound(GLASS_BREAKING,spriteNum);
         A_SpawnWallGlass(spriteNum,-1,10);
@@ -2230,7 +2230,7 @@ void A_DamageObject_Internal(int spriteNum, int const dmgSrc)
     case JURYGUY__STATIC:
         A_PlaySound(SLT(spriteNum),spriteNum);
         A_Spawn(spriteNum,SHT(spriteNum));
-        /* fall-through */
+        fallthrough__;
     case SPACEMARINE__STATIC:
         sprite[spriteNum].extra -= sprite[dmgSrc].extra;
         if (sprite[spriteNum].extra > 0) break;
@@ -2288,7 +2288,7 @@ void A_DamageObject_Internal(int spriteNum, int const dmgSrc)
 
     case PLAYERONWATER__STATIC:
         spriteNum = OW(spriteNum);
-        /* fall-through */
+        fallthrough__;
     default:
         if ((sprite[spriteNum].cstat&16) && SHT(spriteNum) == 0 && SLT(spriteNum) == 0 && sprite[spriteNum].statnum == STAT_DEFAULT)
             break;