--- gif2apng-1.9-src/Makefile
+++ gif2apng-1.9-src/Makefile
@@ -1,10 +1,9 @@
 PACKAGE    = gif2apng
 CC         = gcc
 SRC_DIRS   = . 7z zopfli
-CFLAGS     = -Wall -pedantic
-CFLAGS_OPT = -O2
+CFLAGS     += -Wall -pedantic
+CFLAGS_OPT =
 CFLAGS_7Z  = -Wno-sign-compare -Wno-reorder -Wno-maybe-uninitialized -Wno-parentheses
-LDFLAGS    = -s
 LIBS       = -lstdc++ -lm -lz
 
 INCUDE_DIRS := $(addprefix -I./, $(SRC_DIRS))