diff --git a/src/gui/editors/displaytabs/Makefile.am b/src/gui/editors/displaytabs/Makefile.am
index 73a8619f2..615a008b1 100644
--- a/src/gui/editors/displaytabs/Makefile.am
+++ b/src/gui/editors/displaytabs/Makefile.am
@@ -52,7 +52,7 @@ pkgpyexecdir = @pkgpyexecdir@/gui/editors/displaytabs
 pkgpythondir = @pkgpythondir@/gui/editors/displaytabs
 
 # clean up all the byte-compiled files
-MOSTLYcLEANFILES = *pyc *pyo
+MOSTLYCLEANFILES = *pyc *pyo
 
 GRAMPS_PY_MODPATH = "../../../"