diff --git a/src/api.jl b/src/api.jl
index 16b1acd..9a63ccf 100644
--- a/src/api.jl
+++ b/src/api.jl
@@ -45,7 +45,7 @@ struct MYSQL_FIELD
     field_type::Cuint            ##  Type of field. See mysql_com.h for types
     extension::Ptr{Cvoid}
 end
-nullable(field) = (field.flags & API.NOT_NULL_FLAG) > 0
+notnullable(field) = (field.flags & API.NOT_NULL_FLAG) > 0
 isunsigned(field) = (field.flags & API.UNSIGNED_FLAG) > 0
 
 """
diff --git a/src/consts.jl b/src/consts.jl
index 93f7328..9857b8e 100644
--- a/src/consts.jl
+++ b/src/consts.jl
@@ -35,6 +35,7 @@ struct Bit
     bits::UInt64
 end
 Base.show(io::IO, b::Bit) = print(io, "MySQL.API.Bit(\"$(lstrip(bitstring(b.bits), '0'))\")")
+Base.unsigned(::Type{Bit}) = Bit
 
 mysql_type(::Type{Bit}) = MYSQL_TYPE_BIT
 mysql_type(::Type{Cchar}) = MYSQL_TYPE_TINY
diff --git a/src/types.jl b/src/types.jl
index 00da3b3..97f9000 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -55,10 +55,10 @@ mutable struct Query{hasresult, names, T}
     nrows::Int
 end
 
-function julia_type(field_type, nullable, isunsigned)
+function julia_type(field_type, notnullable, isunsigned)
     T = API.julia_type(field_type)
     T2 = isunsigned ? unsigned(T) : T
-    return nullable ? Union{Missing, T2} : T2
+    return notnullable ? T2 : Union{Missing, T2}
 end
 
 function MySQLRowIterator(args...)
@@ -78,7 +78,7 @@ function Query(conn::Connection, sql::String; kwargs...)
         nrows = MySQL.API.mysql_num_rows(result.ptr)
         fields = MySQL.metadata(result.ptr)
         names = Tuple(ccall(:jl_symbol_n, Ref{Symbol}, (Ptr{UInt8}, Csize_t), x.name, x.name_length) for x in fields)
-        T = Tuple{(julia_type(x.field_type, API.nullable(x), API.isunsigned(x)) for x in fields)...}
+        T = Tuple{(julia_type(x.field_type, API.notnullable(x), API.isunsigned(x)) for x in fields)...}
         hasresult = true
         ncols = length(fields)
         ptr = MySQL.API.mysql_fetch_row(result.ptr)