diff --git a/python-biopython.spec b/python-biopython.spec
index ef71202..d0450c8 100644
--- a/python-biopython.spec
+++ b/python-biopython.spec
@@ -50,7 +50,6 @@ Summary:  Python tools for computational molecular biology
 
 # Build required packages
 BuildRequires:    python2-devel
-#BuildRequires:    flex-devel
 BuildRequires:    %{py2_prefix}-reportlab
 BuildRequires:    %{py2_prefix}-psycopg2
 BuildRequires:    %{py2_prefix}-rdflib
@@ -97,7 +96,6 @@ Summary: Python3 tools for computational molecular biology
 
 BuildRequires:    python%{python3_pkgversion}-devel
 BuildRequires:    python%{python3_pkgversion}-setuptools
-#BuildRequires:    flex-devel
 BuildRequires:    python%{python3_pkgversion}-reportlab
 BuildRequires:    python%{python3_pkgversion}-numpy
 BuildRequires:    python%{python3_pkgversion}-mysql
@@ -127,7 +125,6 @@ Summary: Python3 tools for computational molecular biology
 %{?python_provide:%python_provide python%{python3_other_pkgversion}-%{module}}
 
 BuildRequires:    python%{python3_other_pkgversion}-devel
-#BuildRequires:    flex-devel
 BuildRequires:    python%{python3_other_pkgversion}-reportlab
 BuildRequires:    python%{python3_other_pkgversion}-numpy
 BuildRequires:    python%{python3_other_pkgversion}-mysql
@@ -319,7 +316,7 @@ popd
 %changelog
 * Tue Jul 28 2020 Antonio Trande <sagitter@fedoraproject.org> - 1.77-4
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild
-- Remove flex as BR dependency
+- Remove flex as BR dependency (rhbz#1871093)
 
 * Wed Jun 24 2020 Antonio Trande <sagitter@fedoraproject.org> - 1.77-3
 - BuildRequires python3-setuptools explicitly