diff --git a/src/float4.c b/src/float4.c
index 5d5e650..62ce558 100644
--- a/src/float4.c
+++ b/src/float4.c
@@ -1,5 +1,7 @@
 #include "postgres.h"
 
+#include <math.h>
+
 #include "utils/array.h"
 
 /*