diff --git a/python-cffsubr.spec b/python-cffsubr.spec
index 12a50dd..438081f 100644
--- a/python-cffsubr.spec
+++ b/python-cffsubr.spec
@@ -26,8 +26,8 @@ BuildRequires:  python3-devel
 BuildRequires:  python3dist(setuptools-scm)
 
 %global txbin /usr/bin/tx
-
-BuildRequires:  %{txbin}
+# For the unbundled “tx” executable:
+BuildRequires:  adobe-afdko
 BuildRequires:  symlinks
 
 %description
@@ -39,7 +39,8 @@ Standalone CFF subroutinizer based on the AFDKO tx tool.
 %package -n python3-cffsubr
 Summary:        %{summary}
 
-Requires:       %{txbin}
+# For the unbundled “tx” executable:
+Requires:       adobe-afdko
 
 %description -n python3-cffsubr
 Standalone CFF subroutinizer based on the AFDKO tx tool.