diff --git a/Makefile b/Makefile
index 276d75d..641e726 100644
--- a/Makefile
+++ b/Makefile
@@ -48,7 +48,7 @@ cc-option = $(shell if $(CC) $(1) -c -x c /dev/null -o /dev/null \
 	      1>&2 2>/dev/null; then echo $(1); fi)
 
 override CFLAGS :=							\
-	-O2 -fomit-frame-pointer -std=c99 -I. -Wall -Wundef		\
+	-fomit-frame-pointer -std=c99 -I. -Wall -Wundef		\
 	$(call cc-option,-Wpedantic)					\
 	$(call cc-option,-Wdeclaration-after-statement)			\
 	$(call cc-option,-Wmissing-prototypes)				\
@@ -111,7 +111,7 @@ else ifeq ($(shell uname),Darwin)
    SHARED_LIB         := libdeflate.$(SOVERSION).dylib
    SHARED_LIB_SYMLINK := libdeflate.dylib
    SHARED_LIB_CFLAGS  := -fPIC
-   SHARED_LIB_LDFLAGS := -install_name $(SHARED_LIB)
+   SHARED_LIB_LDFLAGS := -install_name @rpath/$(SHARED_LIB)
 
 # Linux, FreeBSD, etc.
 else
diff --git a/Makefile.msc b/Makefile.msc
index 1449618..a61c034 100644
--- a/Makefile.msc
+++ b/Makefile.msc
@@ -7,11 +7,10 @@
 
 .SUFFIXES: .c .obj .dllobj
 
-CC = cl
+CC = $(CC)
 LD = link
 AR = lib
-CFLAGS = /MD /O2 -I.
-LDFLAGS =
+CFLAGS = /nologo $(CFLAGS) -I.
 
 STATIC_LIB = libdeflatestatic.lib
 SHARED_LIB = libdeflate.dll