diff -ruN fasthenry-3.0wr.orig/src/fasthenry/mk_syscfg.inc fasthenry-3.0wr/src/fasthenry/mk_syscfg.inc
--- fasthenry-3.0wr.orig/src/fasthenry/mk_syscfg.inc	2020-07-23 01:18:06.000000000 +0300
+++ fasthenry-3.0wr/src/fasthenry/mk_syscfg.inc	2020-10-18 23:01:19.019207947 +0300
@@ -2,7 +2,7 @@
 # except for MinGW.
 
 #CFLAGS = -O -g -DFOUR
-CFLAGS = -O3 -DFOUR
+CFLAGS += -DFOUR
 
 # For MinGW, there is no getrusage, and we'll skip a gethostname call
 # to avoid having to link with winsock.
@@ -12,4 +12,4 @@
 
 # We're going to assume gcc, you'll need to comment this if a
 # non-compatible compiler is used.
-CC := gcc
+#CC := gcc
diff -ruN fasthenry-3.0wr.orig/src/sparse/Makefile fasthenry-3.0wr/src/sparse/Makefile
--- fasthenry-3.0wr.orig/src/sparse/Makefile	2019-09-02 21:41:53.000000000 +0300
+++ fasthenry-3.0wr/src/sparse/Makefile	2020-10-18 23:01:49.339387549 +0300
@@ -4,7 +4,7 @@
 #  UC Berkeley
 #
 #CFLAGS = -O -g
-CFLAGS = -O3
+#CFLAGS = -O3
 LINTFLAGS = -lc -lm
 SHELL = /bin/sh
 #CC = cc
diff -ruN fasthenry-3.0wr.orig/src/zbuf/mk_syscfg.inc fasthenry-3.0wr/src/zbuf/mk_syscfg.inc
--- fasthenry-3.0wr.orig/src/zbuf/mk_syscfg.inc	2020-07-23 01:18:23.000000000 +0300
+++ fasthenry-3.0wr/src/zbuf/mk_syscfg.inc	2020-10-18 23:01:19.019207947 +0300
@@ -2,7 +2,7 @@
 # except for MinGW.
 
 #CFLAGS = -O -g -DFOUR
-CFLAGS = -O3 -DFOUR
+CFLAGS += -DFOUR
 
 # For MinGW, there is no getrusage, and we'll skip a gethostname call
 # to avoid having to link with winsock.
@@ -12,4 +12,4 @@
 
 # We're going to assume gcc, you'll need to comment this if a
 # non-compatible compiler is used.
-CC := gcc
+#CC := gcc