diff --git a/include/random.h b/include/random.h
index 85ff71abf..6bf61de6c 100644
--- a/include/random.h
+++ b/include/random.h
@@ -10,6 +10,9 @@ u16 Random2(void);
 
 //Returns a 32-bit pseudorandom number
 #define Random32() (Random() | (Random() << 16))
+
+// The number 1103515245 comes from the example implementation of rand and srand
+// in the ISO C standard.
 #define ISO_RANDOMIZE1(val)(1103515245 * (val) + 24691)
 #define ISO_RANDOMIZE2(val)(1103515245 * (val) + 12345)
 
diff --git a/src/field_weather_effect.c b/src/field_weather_effect.c
index 5a48f3434..26a7adf27 100644
--- a/src/field_weather_effect.c
+++ b/src/field_weather_effect.c
@@ -559,8 +559,7 @@ static void StartRainSpriteFall(struct Sprite *sprite)
     if (sprite->tRandom == 0)
         sprite->tRandom = 361;
 
-    // Standard RNG sequence.
-    rand = sprite->tRandom * 1103515245 + 12345;
+    rand = ISO_RANDOMIZE2(sprite->tRandom);
     sprite->tRandom = ((rand & 0x7FFF0000) >> 16) % 600;
 
     numFallingFrames = sRainSpriteFallingDurations[gWeatherPtr->isDownpour][0];
diff --git a/src/lottery_corner.c b/src/lottery_corner.c
index bb3bb7a5c..5f68ad516 100644
--- a/src/lottery_corner.c
+++ b/src/lottery_corner.c
@@ -35,7 +35,7 @@ void SetRandomLotteryNumber(u16 i)
     u32 var = Random();
 
     while (--i != 0xFFFF)
-        var = var * 1103515245 + 12345;
+        var = ISO_RANDOMIZE2(var);
 
     SetLotteryNumber(var);
 }
diff --git a/src/pokemon_jump.c b/src/pokemon_jump.c
index 11f88d1cf..6c76b15a6 100755
--- a/src/pokemon_jump.c
+++ b/src/pokemon_jump.c
@@ -1674,8 +1674,7 @@ static void sub_802BF7C(void)
 
 static int sub_802C098(void)
 {
-    // The number 1103515245 comes from the example implementation of rand and srand
-    gUnknown_02022CFC->unk24 = gUnknown_02022CFC->unk24 * 1103515245 + 24691;
+    gUnknown_02022CFC->unk24 = ISO_RANDOMIZE1(gUnknown_02022CFC->unk24);
     return gUnknown_02022CFC->unk24 >> 16;
 }
 
diff --git a/src/random.c b/src/random.c
index b570a7bc3..de923fba6 100644
--- a/src/random.c
+++ b/src/random.c
@@ -1,9 +1,6 @@
 #include "global.h"
 #include "random.h"
 
-// The number 1103515245 comes from the example implementation of rand and srand
-// in the ISO C standard.
-
 EWRAM_DATA static u8 sUnknown = 0;
 EWRAM_DATA static u32 sRandCount = 0;
 
@@ -13,7 +10,7 @@ u32 gRng2Value;
 
 u16 Random(void)
 {
-    gRngValue = 1103515245 * gRngValue + 24691;
+    gRngValue = ISO_RANDOMIZE1(gRngValue);
     sRandCount++;
     return gRngValue >> 16;
 }
@@ -31,6 +28,6 @@ void SeedRng2(u16 seed)
 
 u16 Random2(void)
 {
-    gRng2Value = 1103515245 * gRng2Value + 24691;
+    gRng2Value = ISO_RANDOMIZE1(gRng2Value);
     return gRng2Value >> 16;
 }
diff --git a/src/script_pokemon_util_80F87D8.c b/src/script_pokemon_util_80F87D8.c
index 243125448..134004fd0 100755
--- a/src/script_pokemon_util_80F87D8.c
+++ b/src/script_pokemon_util_80F87D8.c
@@ -434,7 +434,7 @@ void ScriptRandom(void)
 
     if (gLinkContestFlags & LINK_CONTEST_FLAG_IS_LINK)
     {
-        gContestRngValue = 1103515245 * gContestRngValue + 24691;
+        gContestRngValue = ISO_RANDOMIZE1(gContestRngValue);
         random = gContestRngValue >> 16;
         scriptPtr = &gSpecialVar_Result;
     }
@@ -448,7 +448,7 @@ void ScriptRandom(void)
 
 u16 GetContestRand(void)
 {
-    gContestRngValue = 1103515245 * gContestRngValue + 24691;
+    gContestRngValue = ISO_RANDOMIZE1(gContestRngValue);
     return gContestRngValue >> 16;
 }
 
diff --git a/src/time_events.c b/src/time_events.c
index bd51f0c2d..3f56d3ab5 100644
--- a/src/time_events.c
+++ b/src/time_events.c
@@ -33,7 +33,7 @@ void UpdateMirageRnd(u16 days)
     s32 rnd = GetMirageRnd();
     while (days)
     {
-        rnd = 1103515245 * rnd + 12345;
+        rnd = ISO_RANDOMIZE2(rnd);
         days--;
     }
     SetMirageRnd(rnd);
diff --git a/src/water.c b/src/water.c
index 760900702..1a66835fb 100644
--- a/src/water.c
+++ b/src/water.c
@@ -1762,7 +1762,7 @@ void sub_810871C(struct Task *task, u8 taskId)
     }
     task->data[11]++;
     task->data[8] = (task->data[8] + 39) & 0xFF;
-    task->data[7] = ((task->data[7] * 1103515245 + 12345) % task->data[5]) + task->data[4];
+    task->data[7] = (ISO_RANDOMIZE2(task->data[7]) % task->data[5]) + task->data[4];
 }
 
 void sub_81087C0(struct Sprite *sprite)
diff --git a/src/wild_encounter.c b/src/wild_encounter.c
index 52aac17f3..21f871751 100644
--- a/src/wild_encounter.c
+++ b/src/wild_encounter.c
@@ -127,12 +127,9 @@ static bool8 CheckFeebas(void)
     return FALSE;
 }
 
-// The number 1103515245 comes from the example implementation of rand and srand
-// in the ISO C standard.
-
 static u16 FeebasRandom(void)
 {
-    sFeebasRngValue = (1103515245 * sFeebasRngValue) + 12345;
+    sFeebasRngValue = ISO_RANDOMIZE2(sFeebasRngValue);
     return sFeebasRngValue >> 16;
 }