diff --git a/pagure/lib/__init__.py b/pagure/lib/__init__.py
index 2acbaaf..4216207 100644
--- a/pagure/lib/__init__.py
+++ b/pagure/lib/__init__.py
@@ -2373,5 +2373,6 @@ def could_be_text(text):
     """
     try:
         text.encode('utf-8')
-    except:
         return True
+    except:
+        return False
diff --git a/pagure/ui/repo.py b/pagure/ui/repo.py
index e603aa1..da200c6 100644
--- a/pagure/ui/repo.py
+++ b/pagure/ui/repo.py
@@ -354,7 +354,7 @@ def view_file(repo, identifier, filename, username=None):
         content = commit
 
     if isinstance(content, pygit2.Blob):
-        if content.is_binary or pagure.lib.could_be_text(data):
+        if content.is_binary or not pagure.lib.could_be_text(data):
             ext = filename[filename.rfind('.'):]
             if ext in (
                     '.gif', '.png', '.bmp', '.tif', '.tiff', '.jpg',
@@ -1302,7 +1302,7 @@ def edit_file(repo, branchname, filename, username=None):
             flask.abort(404, 'File not found')
 
         data = repo_obj[content.oid].data
-        if content.is_binary or pagure.lib.could_be_text(data):
+        if content.is_binary or not pagure.lib.could_be_text(data):
             flask.abort(400, 'Cannot edit binary files')
     else:
         data = form.content.data