diff --git a/GNUmakefile b/GNUmakefile
index 3b0016b..d3729e5 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -43,7 +43,7 @@ ifeq ($(IS_WATCOM),1)
 	LDFLAGS =
 	LIBS =
 
-	ifeq ($(IS_),1)
+	ifeq ($(IS_WINDOWS),1)
 		CC += -bnt
 	endif
 endif
@@ -56,7 +56,7 @@ ifeq ($(IS_MINGW),1)
 endif
 
 ifeq ($(IS_MUSL_CROSS),1)
-	CC = musl-$(CC)
+	CC = musl-gcc
 endif
 
 ### Common flags