diff --git a/src/app/components/SlotSection.jsx b/src/app/components/SlotSection.jsx
index 6f300e8e..e6f75da4 100644
--- a/src/app/components/SlotSection.jsx
+++ b/src/app/components/SlotSection.jsx
@@ -129,44 +129,46 @@ export default class SlotSection extends TranslatedComponent {
     let { originSlot, targetSlot, copy } = this.state;
     let m = originSlot.m;
 
-    if (copy) {
-      // We want to copy the module in to the target slot
-      if (targetSlot && canMount(this.props.ship, targetSlot, m.grp, m.class)) {
-        const mCopy = m.clone();
-        this.props.ship.use(targetSlot, mCopy, false);
-        // Copy power info
-        targetSlot.enabled = originSlot.enabled;
-        targetSlot.priority = originSlot.priority;
-        this.props.onChange();
-      }
-    } else {
-      // Store power info
-      const originEnabled = targetSlot.enabled;
-      const originPriority = targetSlot.priority;
-      const targetEnabled = originSlot.enabled;
-      const targetPriority = originSlot.priority;
-      // We want to move the module in to the target slot, and swap back any module that was originally in the target slot
-      if (targetSlot && m && canMount(this.props.ship, targetSlot, m.grp, m.class)) {
-        // Swap modules if possible
-        if (targetSlot.m && canMount(this.props.ship, originSlot, targetSlot.m.grp, targetSlot.m.class)) {
-          this.props.ship.use(originSlot, targetSlot.m, true);
-          this.props.ship.use(targetSlot, m);
-          // Swap power
-          originSlot.enabled = originEnabled;
-          originSlot.priority = originPriority;
-          targetSlot.enabled = targetEnabled;
-          targetSlot.priority = targetPriority;
-        } else { // Otherwise empty the origin slot
-          // Store power
-          const targetEnabled = originSlot.enabled;
-          this.props.ship.use(originSlot, null, true);  // Empty but prevent summary update
-          this.props.ship.use(targetSlot, m);
-          originSlot.enabled = 0;
-          originSlot.priority = 0;
-          targetSlot.enabled = targetEnabled;
-          targetSlot.priority = targetPriority;
+    if (targetSlot && originSlot != targetSlot) {
+      if (copy) {
+        // We want to copy the module in to the target slot
+        if (targetSlot && canMount(this.props.ship, targetSlot, m.grp, m.class)) {
+          const mCopy = m.clone();
+          this.props.ship.use(targetSlot, mCopy, false);
+          // Copy power info
+          targetSlot.enabled = originSlot.enabled;
+          targetSlot.priority = originSlot.priority;
+          this.props.onChange();
+        }
+      } else {
+        // Store power info
+        const originEnabled = targetSlot.enabled;
+        const originPriority = targetSlot.priority;
+        const targetEnabled = originSlot.enabled;
+        const targetPriority = originSlot.priority;
+        // We want to move the module in to the target slot, and swap back any module that was originally in the target slot
+        if (targetSlot && m && canMount(this.props.ship, targetSlot, m.grp, m.class)) {
+          // Swap modules if possible
+          if (targetSlot.m && canMount(this.props.ship, originSlot, targetSlot.m.grp, targetSlot.m.class)) {
+            this.props.ship.use(originSlot, targetSlot.m, true);
+            this.props.ship.use(targetSlot, m);
+            // Swap power
+            originSlot.enabled = originEnabled;
+            originSlot.priority = originPriority;
+            targetSlot.enabled = targetEnabled;
+            targetSlot.priority = targetPriority;
+          } else { // Otherwise empty the origin slot
+            // Store power
+            const targetEnabled = originSlot.enabled;
+            this.props.ship.use(originSlot, null, true);  // Empty but prevent summary update
+            this.props.ship.use(targetSlot, m);
+            originSlot.enabled = 0;
+            originSlot.priority = 0;
+            targetSlot.enabled = targetEnabled;
+            targetSlot.priority = targetPriority;
+          }
+          this.props.onChange();
         }
-        this.props.onChange();
       }
     }
     this.setState({ originSlot: null, targetSlot: null, copy: null });