diff --git a/src/components/fields/NumberField.jsx b/src/components/fields/NumberField.jsx
index 05ea38c2..24e4b334 100644
--- a/src/components/fields/NumberField.jsx
+++ b/src/components/fields/NumberField.jsx
@@ -25,12 +25,20 @@ class NumberField extends React.Component {
   }
 
   render() {
+    let stepSize = null
+    if(this.props.max && this.props.min) {
+      stepSize = (this.props.max - this.props.min) / 10
+    }
+
     return <input
       style={{
         ...input.input,
         ...this.props.style
       }}
       type="number"
+      min={this.props.min}
+      max={this.props.max}
+      step={stepSize}
       name={this.props.name}
       placeholder={this.props.default}
       value={this.props.value}
diff --git a/src/components/fields/SpecField.jsx b/src/components/fields/SpecField.jsx
index 1ccdef0a..023825aa 100644
--- a/src/components/fields/SpecField.jsx
+++ b/src/components/fields/SpecField.jsx
@@ -49,8 +49,8 @@ export default class SpecField extends React.Component {
         <NumberField
           {...commonProps}
           default={this.props.fieldSpec.default}
-          min={this.props.fieldSpec.min}
-          max={this.props.fieldSpec.max}
+          min={this.props.fieldSpec.minimum}
+          max={this.props.fieldSpec.maximum}
           unit={this.props.fieldSpec.unit}
         />
       )