diff --git a/lib/gui/models/store.js b/lib/gui/models/store.js
index 7c6bdf93..8a8f62aa 100644
--- a/lib/gui/models/store.js
+++ b/lib/gui/models/store.js
@@ -107,6 +107,34 @@ const storeReducer = (state, action) => {
         throw new Error('Can\'t set the flashing state when not flashing');
       }
 
+      if (!action.data.type) {
+        throw new Error('Missing state type');
+      }
+
+      if (!_.isString(action.data.type)) {
+        throw new Error(`Invalid state type: ${action.data.type}`);
+      }
+
+      if (!action.data.progress) {
+        throw new Error('Missing state progress');
+      }
+
+      if (!_.isNumber(action.data.progress)) {
+        throw new Error(`Invalid state progress: ${action.data.progress}`);
+      }
+
+      if (!action.data.eta) {
+        throw new Error('Missing state eta');
+      }
+
+      if (!_.isNumber(action.data.eta)) {
+        throw new Error(`Invalid state eta: ${action.data.eta}`);
+      }
+
+      if (!action.data.speed) {
+        throw new Error('Missing state speed');
+      }
+
       return state.set('flashState', Immutable.fromJS(action.data));
     }
 
diff --git a/tests/gui/modules/image-writer.spec.js b/tests/gui/modules/image-writer.spec.js
index d4faffde..48e3196f 100644
--- a/tests/gui/modules/image-writer.spec.js
+++ b/tests/gui/modules/image-writer.spec.js
@@ -81,6 +81,86 @@ describe('Browser: ImageWriter', function() {
         }).to.throw('Can\'t set the flashing state when not flashing');
       });
 
+      it('should throw if type is missing', function() {
+        ImageWriterService.setFlashing(true);
+        m.chai.expect(function() {
+          ImageWriterService.setProgressState({
+            percentage: 50,
+            eta: 15,
+            speed: 100000000000
+          });
+        }).to.throw('Missing state type');
+      });
+
+      it('should throw if type is not a string', function() {
+        ImageWriterService.setFlashing(true);
+        m.chai.expect(function() {
+          ImageWriterService.setProgressState({
+            type: 1234,
+            percentage: 50,
+            eta: 15,
+            speed: 100000000000
+          });
+        }).to.throw('Invalid state type: 1234');
+      });
+
+      it('should throw if progress is missing', function() {
+        ImageWriterService.setFlashing(true);
+        m.chai.expect(function() {
+          ImageWriterService.setProgressState({
+            type: 'write',
+            eta: 15,
+            speed: 100000000000
+          });
+        }).to.throw('Missing state progress');
+      });
+
+      it('should throw if progress is not a number', function() {
+        ImageWriterService.setFlashing(true);
+        m.chai.expect(function() {
+          ImageWriterService.setProgressState({
+            type: 'write',
+            percentage: '50',
+            eta: 15,
+            speed: 100000000000
+          });
+        }).to.throw('Invalid state progress: 50');
+      });
+
+      it('should throw if eta is missing', function() {
+        ImageWriterService.setFlashing(true);
+        m.chai.expect(function() {
+          ImageWriterService.setProgressState({
+            type: 'write',
+            percentage: 50,
+            speed: 100000000000
+          });
+        }).to.throw('Missing state eta');
+      });
+
+      it('should throw if eta is not a number', function() {
+        ImageWriterService.setFlashing(true);
+        m.chai.expect(function() {
+          ImageWriterService.setProgressState({
+            type: 'write',
+            percentage: 50,
+            eta: '15',
+            speed: 100000000000
+          });
+        }).to.throw('Invalid state eta: 15');
+      });
+
+      it('should throw if speed is missing', function() {
+        ImageWriterService.setFlashing(true);
+        m.chai.expect(function() {
+          ImageWriterService.setProgressState({
+            type: 'write',
+            percentage: 50,
+            eta: 15
+          });
+        }).to.throw('Missing state speed');
+      });
+
     });
 
     describe('.setFlashing()', function() {