diff --git a/src/Noise.cpp b/src/Noise.cpp
index efbb128c3..95a022ea3 100644
--- a/src/Noise.cpp
+++ b/src/Noise.cpp
@@ -744,6 +744,8 @@ void cCubicNoise::CalcFloorFrac(
 	int * a_Same, int & a_NumSame
 ) const
 {
+	ASSERT(a_Size > 0);
+
 	NOISE_DATATYPE val = a_Start;
 	NOISE_DATATYPE dif = (a_End - a_Start) / (a_Size - 1);
 	for (int i = 0; i < a_Size; i++)