diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 7cf56568f3..682200f636 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -10290,7 +10290,7 @@ power_var_int(const NumericVar *base, int exp, NumericVar *result, int rscale)
 	 * to around log10(abs(exp)) digits, so work with this many extra digits
 	 * of precision (plus a few more for good measure).
 	 */
-	sig_digits += (int) log(fabs(exp)) + 8;
+	sig_digits += (int) log(fabs((double) exp)) + 8;
 
 	/*
 	 * Now we can proceed with the multiplications.