--- gmic-3.7.6.old/gmic-qt/gmic_qt.pro
+++ gmic-3.7.6/gmic-qt/gmic_qt.pro
@@ -16,7 +16,7 @@
 }
 
 # Possible values are "gcc" or "clang"
-!defined(COMPILER,var) { COMPILER = gcc }
+!defined(COMPILER,var) { COMPILER = clang }
 
 # Possible values are "on" or "off"
 !defined(LTO,var) { LTO=off }
--- gmic-3.7.6.old/src/Makefile
+++ gmic-3.7.6/src/Makefile
@@ -210,8 +210,8 @@
 OPT_LIBS = # $(FLTO)
 endif
 ifdef IS_CLANG
-OPT_CFLAGS = -O3 -mtune=generic --stdlib=libc++ # '-Ofast' makes things unstable
-OPT_LIBS = $(FLTO)
+OPT_CFLAGS = -O3 -mtune=generic
+OPT_LIBS =
 endif
 ifdef IS_ICPC
 OPT_CFLAGS = -fast