diff --git a/qutebrowser/utils/completion.py b/qutebrowser/utils/completion.py
index bd094f741..bec71ee24 100644
--- a/qutebrowser/utils/completion.py
+++ b/qutebrowser/utils/completion.py
@@ -99,6 +99,9 @@ class CompletionModel(QAbstractItemModel):
 
         return len(pitem.children)
 
+    def sort(self, column, order=Qt.AscendingOrder):
+        raise NotImplementedError
+
     def init_data(self):
         for (cat, items) in self._data.items():
             newcat = CompletionItem([cat], self.root)
@@ -145,7 +148,7 @@ class CompletionItem():
 
 class CompletionFilterModel(QSortFilterProxyModel):
     _pattern = None
-    # FIXME sort in a way strings starting with pattern are first
+    pattern_changed = pyqtSignal(str)
 
     @property
     def pattern(self):
@@ -154,7 +157,8 @@ class CompletionFilterModel(QSortFilterProxyModel):
     @pattern.setter
     def pattern(self, val):
         self._pattern = val
-        self.invalidateFilter()
+        self.invalidate()
+        self.pattern_changed.emit(val)
 
     def __init__(self, parent=None):
         super().__init__(parent)
@@ -169,3 +173,19 @@ class CompletionFilterModel(QSortFilterProxyModel):
         if not self.pattern:
             return True
         return self.pattern in data
+
+    def lessThan(self, lindex, rindex):
+        left = self.sourceModel().data(lindex).value()
+        right = self.sourceModel().data(rindex).value()
+
+        leftstart = left.startswith(self.pattern)
+        rightstart = right.startswith(self.pattern)
+
+        if leftstart and rightstart:
+            return left < right
+        elif leftstart:
+            return True
+        elif rightstart:
+            return False
+        else:
+            return left < right
diff --git a/qutebrowser/widgets/completion.py b/qutebrowser/widgets/completion.py
index 63ea3a45d..947a33f22 100644
--- a/qutebrowser/widgets/completion.py
+++ b/qutebrowser/widgets/completion.py
@@ -51,6 +51,7 @@ class CompletionView(QTreeView):
         self.model = CompletionFilterModel()
         self.setModel(self.model)
         self.model.setSourceModel(self.completion_models['command'])
+        self.model.pattern_changed.connect(self.resort)
         self.setItemDelegate(CompletionItemDelegate())
         self.setStyleSheet(self._stylesheet.strip())
         self.expandAll()
@@ -71,6 +72,12 @@ class CompletionView(QTreeView):
         self.model.pattern = ''
         self.expandAll()
 
+    def resort(self, pattern):
+        try:
+            self.model.sourceModel().sort(0)
+        except NotImplementedError:
+            self.model.sort(0)
+
     def resize_to_bar(self, geom):
         bottomleft = geom.topLeft()
         bottomright = geom.topRight()