diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index e5c7e57a5d..1640d83885 100644
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -3404,6 +3404,12 @@ construct_array_builtin(Datum *elems, int nelems, Oid elmtype)
 			elmalign = TYPALIGN_INT;
 			break;
 
+		case FLOAT8OID:
+			elmlen = sizeof(float8);
+			elmbyval = FLOAT8PASSBYVAL;
+			elmalign = TYPALIGN_DOUBLE;
+			break;
+
 		case INT2OID:
 			elmlen = sizeof(int16);
 			elmbyval = true;
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index f709c21e1f..6fa6ffb51f 100644
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -2946,9 +2946,7 @@ float8_combine(PG_FUNCTION_ARGS)
 		transdatums[1] = Float8GetDatumFast(Sx);
 		transdatums[2] = Float8GetDatumFast(Sxx);
 
-		result = construct_array(transdatums, 3,
-								 FLOAT8OID,
-								 sizeof(float8), FLOAT8PASSBYVAL, TYPALIGN_DOUBLE);
+		result = construct_array_builtin(transdatums, 3, FLOAT8OID);
 
 		PG_RETURN_ARRAYTYPE_P(result);
 	}
@@ -3029,9 +3027,7 @@ float8_accum(PG_FUNCTION_ARGS)
 		transdatums[1] = Float8GetDatumFast(Sx);
 		transdatums[2] = Float8GetDatumFast(Sxx);
 
-		result = construct_array(transdatums, 3,
-								 FLOAT8OID,
-								 sizeof(float8), FLOAT8PASSBYVAL, TYPALIGN_DOUBLE);
+		result = construct_array_builtin(transdatums, 3, FLOAT8OID);
 
 		PG_RETURN_ARRAYTYPE_P(result);
 	}
@@ -3114,9 +3110,7 @@ float4_accum(PG_FUNCTION_ARGS)
 		transdatums[1] = Float8GetDatumFast(Sx);
 		transdatums[2] = Float8GetDatumFast(Sxx);
 
-		result = construct_array(transdatums, 3,
-								 FLOAT8OID,
-								 sizeof(float8), FLOAT8PASSBYVAL, TYPALIGN_DOUBLE);
+		result = construct_array_builtin(transdatums, 3, FLOAT8OID);
 
 		PG_RETURN_ARRAYTYPE_P(result);
 	}
@@ -3359,9 +3353,7 @@ float8_regr_accum(PG_FUNCTION_ARGS)
 		transdatums[4] = Float8GetDatumFast(Syy);
 		transdatums[5] = Float8GetDatumFast(Sxy);
 
-		result = construct_array(transdatums, 6,
-								 FLOAT8OID,
-								 sizeof(float8), FLOAT8PASSBYVAL, TYPALIGN_DOUBLE);
+		result = construct_array_builtin(transdatums, 6, FLOAT8OID);
 
 		PG_RETURN_ARRAYTYPE_P(result);
 	}
@@ -3500,9 +3492,7 @@ float8_regr_combine(PG_FUNCTION_ARGS)
 		transdatums[4] = Float8GetDatumFast(Syy);
 		transdatums[5] = Float8GetDatumFast(Sxy);
 
-		result = construct_array(transdatums, 6,
-								 FLOAT8OID,
-								 sizeof(float8), FLOAT8PASSBYVAL, TYPALIGN_DOUBLE);
+		result = construct_array_builtin(transdatums, 6, FLOAT8OID);
 
 		PG_RETURN_ARRAYTYPE_P(result);
 	}