Percent encoding routines
diff --git a/config.m4 b/config.m4
index b37658d..2e916ab 100644
--- a/config.m4
+++ b/config.m4
@@ -57,6 +57,7 @@
     src/core/lib/support/log_posix.c \
     src/core/lib/support/log_windows.c \
     src/core/lib/support/murmur_hash.c \
+    src/core/lib/support/percent_encoding.c \
     src/core/lib/support/slice.c \
     src/core/lib/support/slice_buffer.c \
     src/core/lib/support/stack_lockfree.c \