Index: lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
===================================================================
--- lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
+++ lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
@@ -59,6 +59,7 @@
 getpid U
 gettimeofday U
 ioctl U
+isalpha U
 isatty U
 isprint U
 isupper U