--- autoconf/autoscan.pl
+++ autoconf/autoscan.pl
@@ -232,7 +232,7 @@ sub scan_makefile
 	# Strip out comments and variable references.
 	s/#.*//;
 	s/\$\([^\)]*\)//g;
-	s/\${[^\}]*}//g;
+	s/\$\{[^\}]*}//g;
 	s/@[^@]*@//g;
 
 	# Variable assignments.
--- autoconf/autoscan.pl
+++ autoconf/autoscan.pl
@@ -364,7 +364,7 @@ sub output_headers
 	}
     }
     print CONF "AC_CHECK_HEADERS(" . join(' ', sort(@have_headers)) . ")\n"
-	if defined(@have_headers);
+	if @have_headers;
 }
 
 sub output_identifiers
@@ -391,5 +391,5 @@ sub output_functions
 	}
     }
     print CONF "AC_CHECK_FUNCS(" . join(' ', sort(@have_funcs)) . ")\n"
-	if defined(@have_funcs);
+	if @have_funcs;
 }