diff --git a/ChangeLog.md b/ChangeLog.md
index bb6bc4c2..bdca7dd9 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,6 +1,7 @@
 #2.2.10
   * Fix detailed export of module reinforcement packages
   * Use damagedist for exact breakdown of weapons that have more than one type of damage
+  * Use new-style modification validity data
 
 #2.2.9
   * Use SSL-enabled server for shortlinks
diff --git a/src/app/components/HardpointSlot.jsx b/src/app/components/HardpointSlot.jsx
index 8436331b..a8fc6c9f 100644
--- a/src/app/components/HardpointSlot.jsx
+++ b/src/app/components/HardpointSlot.jsx
@@ -41,7 +41,7 @@ export default class HardpointSlot extends Slot {
       let classRating = `${m.class}${m.rating}${m.missile ? '/' + m.missile : ''}`;
       let { drag, drop } = this.props;
       let { termtip, tooltip } = this.context;
-      let validMods = Modifications.validity[m.grp] || [];
+      let validMods = Modifications.modules[m.grp].modifications || [];
       let showModuleResistances = Persist.showModuleResistances();
 
       // Modifications tooltip shows blueprint and grade, if available
diff --git a/src/app/components/InternalSlot.jsx b/src/app/components/InternalSlot.jsx
index 1bb7bf4b..4ce53f83 100644
--- a/src/app/components/InternalSlot.jsx
+++ b/src/app/components/InternalSlot.jsx
@@ -23,7 +23,7 @@ export default class InternalSlot extends Slot {
       let classRating = m.class + m.rating;
       let { drag, drop, ship } = this.props;
       let { termtip, tooltip } = this.context;
-      let validMods = Modifications.validity[m.grp] || [];
+      let validMods = Modifications.modules[m.grp].modifications || [];
       let showModuleResistances = Persist.showModuleResistances();
 
       // Modifications tooltip shows blueprint and grade, if available
diff --git a/src/app/components/ModificationsMenu.jsx b/src/app/components/ModificationsMenu.jsx
index 1a56180f..3ea35c6c 100644
--- a/src/app/components/ModificationsMenu.jsx
+++ b/src/app/components/ModificationsMenu.jsx
@@ -36,15 +36,22 @@ export default class ModificationsMenu extends TranslatedComponent {
    */
   _initState(props, context) {
     let { m, onChange, ship } = props;
-    let list = [];
 
-    for (let modName of Modifications.validity[m.grp]) {
-      if (Modifications.modifications[modName].type != 'hidden') {
-        list.push(<Modification key={ modName } ship={ ship } m={ m } name={ modName } onChange={ onChange }/>);
+    let blueprints = [];
+    for (const blueprintName in Modifications.modules[m.grp].blueprints) {
+      for (const grade of Modifications.modules[m.grp].blueprints[blueprintName]) {
+        blueprints.push(<div>{Modifications.blueprints[blueprintName].name} grade {grade}</div>);
       }
     }
 
-    return { list };
+    let modifications = [];
+    for (const modName of Modifications.modules[m.grp].modifications) {
+      if (Modifications.modifications[modName].type === 'percentage' || Modifications.modifications[modName].type === 'numeric') {
+        modifications.push(<Modification key={ modName } ship={ ship } m={ m } name={ modName } onChange={ onChange }/>);
+      }
+    }
+
+    return { blueprints, modifications };
   }
 
   /**
@@ -60,7 +67,8 @@ export default class ModificationsMenu extends TranslatedComponent {
           onContextMenu={stopCtxPropagation}
           onMouseOver={termtip.bind(null, 'HELP_MODIFICATIONS_MENU')} onMouseOut={tooltip.bind(null, null)} 
       >
-        {this.state.list}
+        {this.state.blueprints}
+        {this.state.modifications}
       </div>
     );
   }
diff --git a/src/app/components/StandardSlot.jsx b/src/app/components/StandardSlot.jsx
index ebbd5485..d032fc00 100644
--- a/src/app/components/StandardSlot.jsx
+++ b/src/app/components/StandardSlot.jsx
@@ -46,7 +46,7 @@ export default class StandardSlot extends TranslatedComponent {
     let m = slot.m;
     let classRating = m.class + m.rating;
     let menu;
-    let validMods = m == null ? [] : (Modifications.validity[m.grp] || []);
+    let validMods = m == null ? [] : (Modifications.modules[m.grp].modifications || []);
     let showModuleResistances = Persist.showModuleResistances();
     let mass = m.getMass() || m.cargo || m.fuel || 0;
 
diff --git a/src/app/shipyard/Ship.js b/src/app/shipyard/Ship.js
index 1f9fd2fc..ed276a60 100755
--- a/src/app/shipyard/Ship.js
+++ b/src/app/shipyard/Ship.js
@@ -1335,7 +1335,7 @@ export default class Ship {
     if (this.bulkheads.m && this.bulkheads.m.mods) {
       for (let modKey in this.bulkheads.m.mods) {
         // Filter out invalid modifications
-        if (Modifications.validity['bh'] && Modifications.validity['bh'].indexOf(modKey) != -1) {
+        if (Modifications.modules['bh'] && Modifications.modules['bh'].modifications.indexOf(modKey) != -1) {
           bulkheadMods.push({ id: Modifications.modifications[modKey].id, value: this.bulkheads.m.getModValue(modKey) });
         }
       }
@@ -1350,7 +1350,7 @@ export default class Ship {
       if (slot.m && slot.m.mods) {
         for (let modKey in slot.m.mods) {
           // Filter out invalid modifications
-          if (Modifications.validity[slot.m.grp] && Modifications.validity[slot.m.grp].indexOf(modKey) != -1) {
+          if (Modifications.modules[slot.m.grp] && Modifications.modules[slot.m.grp].modifications.indexOf(modKey) != -1) {
             slotMods.push({ id: Modifications.modifications[modKey].id, value: slot.m.getModValue(modKey) });
           }
         }
@@ -1365,7 +1365,7 @@ export default class Ship {
       if (slot.m && slot.m.mods) {
         for (let modKey in slot.m.mods) {
           // Filter out invalid modifications
-          if (Modifications.validity[slot.m.grp] && Modifications.validity[slot.m.grp].indexOf(modKey) != -1) {
+          if (Modifications.modules[slot.m.grp] && Modifications.modules[slot.m.grp].modifications.indexOf(modKey) != -1) {
             slotMods.push({ id: Modifications.modifications[modKey].id, value: slot.m.getModValue(modKey) });
           }
         }
@@ -1380,7 +1380,7 @@ export default class Ship {
       if (slot.m && slot.m.mods) {
         for (let modKey in slot.m.mods) {
           // Filter out invalid modifications
-          if (Modifications.validity[slot.m.grp] && Modifications.validity[slot.m.grp].indexOf(modKey) != -1) {
+          if (Modifications.modules[slot.m.grp] && Modifications.modules[slot.m.grp].modifications.indexOf(modKey) != -1) {
             slotMods.push({ id: Modifications.modifications[modKey].id, value: slot.m.getModValue(modKey) });
           }
         }
diff --git a/src/app/utils/SlotFunctions.js b/src/app/utils/SlotFunctions.js
index a9481315..1c064c67 100644
--- a/src/app/utils/SlotFunctions.js
+++ b/src/app/utils/SlotFunctions.js
@@ -153,7 +153,7 @@ export function diffDetails(language, m, mm) {
 
   let mPowerGeneration = m.pgen || 0;
   let mmPowerGeneration = mm ? mm.getPowerGeneration() : 0;
-  if (mPowerGeneration != mmPowerGeneration) propDiffs.push(<div key='pgen'>{translate('pgen')}: <span className={diffClass(mPowerGeneration, mmPowerGeneration, true)}>{diff(formats.round, mPowerGeneration, mmPowerGeneration)}{units.MJ}</span></div>);
+  if (mPowerGeneration != mmPowerGeneration) propDiffs.push(<div key='pgen'>{translate('pgen')}: <span className={diffClass(mPowerGeneration, mmPowerGeneration)}>{diff(formats.round, mPowerGeneration, mmPowerGeneration)}{units.MJ}</span></div>);
 
   let mPowerUsage = m.power || 0;
   let mmPowerUsage = mm ? mm.getPowerUsage() : 0;