diff --git a/app-text/calibre/calibre-8.4.0.ebuild b/app-text/calibre/calibre-8.4.0.ebuild
index 40526d6051f81..0ed7122b5d8d0 100644
--- a/app-text/calibre/calibre-8.4.0.ebuild
+++ b/app-text/calibre/calibre-8.4.0.ebuild
@@ -224,7 +224,7 @@ src_install() {
 	#    raise ValueError, 'unknown locale: %s' % localename
 	#ValueError: unknown locale: 46
 	export -n LANG LANGUAGE ${!LC_*}
-	export LC_ALL=C.utf8 # bug #709682
+	export LC_ALL=C.UTF-8 # bug #709682
 
 	# Bug #295672 - Avoid sandbox violation in ~/.config by forcing
 	# variables to point to our fake temporary $HOME.
diff --git a/app-text/calibre/calibre-8.7.0.ebuild b/app-text/calibre/calibre-8.7.0.ebuild
index ac99f9de130d0..b7f5471f7ba2f 100644
--- a/app-text/calibre/calibre-8.7.0.ebuild
+++ b/app-text/calibre/calibre-8.7.0.ebuild
@@ -222,7 +222,7 @@ src_install() {
 	#    raise ValueError, 'unknown locale: %s' % localename
 	#ValueError: unknown locale: 46
 	export -n LANG LANGUAGE ${!LC_*}
-	export LC_ALL=C.utf8 # bug #709682
+	export LC_ALL=C.UTF-8 # bug #709682
 
 	# Bug #295672 - Avoid sandbox violation in ~/.config by forcing
 	# variables to point to our fake temporary $HOME.
diff --git a/app-text/calibre/calibre-8.9.0.ebuild b/app-text/calibre/calibre-8.9.0.ebuild
index 3b7b0d71b8aae..18f53d2e86ca9 100644
--- a/app-text/calibre/calibre-8.9.0.ebuild
+++ b/app-text/calibre/calibre-8.9.0.ebuild
@@ -223,7 +223,7 @@ src_install() {
 	#    raise ValueError, 'unknown locale: %s' % localename
 	#ValueError: unknown locale: 46
 	export -n LANG LANGUAGE ${!LC_*}
-	export LC_ALL=C.utf8 # bug #709682
+	export LC_ALL=C.UTF-8 # bug #709682
 
 	# Bug #295672 - Avoid sandbox violation in ~/.config by forcing
 	# variables to point to our fake temporary $HOME.