diff --git a/Makefile b/Makefile
index 69fe65e..4f3cca0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 
 CC = gcc
 STND=-ansi
-CFLAGS = $(STND) -pedantic -O0 -g -Wall -Werror -Wextra -Wformat=2 -Wshadow \
+CFLAGS = $(STND) -pedantic -O3 -g -Wall -Werror -Wextra -Wformat=2 -Wshadow \
   -Wno-long-long -Wno-overlength-strings -Wno-format-nonliteral -Wcast-align \
   -Wwrite-strings -Wstrict-prototypes -Wold-style-definition -Wredundant-decls \
   -Wnested-externs -Wmissing-include-dirs -Wswitch-default
diff --git a/mpc.c b/mpc.c
index d3934da..0bed4c1 100644
--- a/mpc.c
+++ b/mpc.c
@@ -2301,7 +2301,7 @@ mpc_val_t *mpcf_trd_free(int n, mpc_val_t **xs) { return mpcf_nth_free(n, xs, 2)
 
 mpc_val_t *mpcf_strfold(int n, mpc_val_t **xs) {
   int i;
-  size_t l;
+  size_t l = 0;
   
   if (n == 0) { return calloc(1, 1); }