diff --git a/Materials/platforms/inweb-on-windows.mk b/Materials/platforms/inweb-on-windows.mk
index aab02f7..2718e22 100644
--- a/Materials/platforms/inweb-on-windows.mk
+++ b/Materials/platforms/inweb-on-windows.mk
@@ -12,7 +12,7 @@ EXEEXTENSION = .exe
 INTEST = intest/Tangled/intest
 INWEB = inweb/Tangled/inweb
 
-CCOPTS = -DPLATFORM_WINDOWS=1 -D_WIN32_WINNT=0x0600
+CCOPTS = -DPLATFORM_WINDOWS=1 -D_WIN32_WINNT=0x0600 $(CFLAGS)
 
 MANYWARNINGS = -Weverything -Wno-pointer-arith -Wno-unused-macros -Wno-shadow -Wno-cast-align -Wno-variadic-macros -Wno-missing-noreturn -Wno-missing-prototypes -Wno-unused-parameter -Wno-padded -Wno-missing-variable-declarations -Wno-unreachable-code-break -Wno-class-varargs -Wno-format-nonliteral -Wno-cast-qual -Wno-double-promotion -Wno-comma -Wno-strict-prototypes -Wno-extra-semi-stmt -Wno-used-but-marked-unused -Wno-unreachable-code-return -ferror-limit=1000
 
diff --git a/Materials/platforms/windows.mk b/Materials/platforms/windows.mk
index 7e20988..3f1bfdc 100644
--- a/Materials/platforms/windows.mk
+++ b/Materials/platforms/windows.mk
@@ -12,7 +12,7 @@ EXEEXTENSION = .exe
 INTEST = intest/Tangled/intest
 INWEB = inweb/Tangled/inweb
 
-CCOPTS = -DPLATFORM_WINDOWS=1 -D_WIN32_WINNT=0x0600
+CCOPTS = -DPLATFORM_WINDOWS=1 -D_WIN32_WINNT=0x0600 $(CFLAGS)
 
 MANYWARNINGS = -Weverything -Wno-pointer-arith -Wno-unused-macros -Wno-shadow -Wno-cast-align -Wno-variadic-macros -Wno-missing-noreturn -Wno-missing-prototypes -Wno-unused-parameter -Wno-padded -Wno-missing-variable-declarations -Wno-unreachable-code-break -Wno-class-varargs -Wno-format-nonliteral -Wno-cast-qual -Wno-double-promotion -Wno-comma -Wno-strict-prototypes -Wno-extra-semi-stmt -Wno-used-but-marked-unused -Wno-unreachable-code-return -ferror-limit=1000
 
diff --git a/Materials/platforms/windows.mkscript b/Materials/platforms/windows.mkscript
index 4af237d..7792c20 100644
--- a/Materials/platforms/windows.mkscript
+++ b/Materials/platforms/windows.mkscript
@@ -79,7 +79,7 @@ INWEB = inweb/Tangled/inweb
 
 # Where:
 
-CCOPTS = -DPLATFORM_WINDOWS=1 -D_WIN32_WINNT=0x0600
+CCOPTS = -DPLATFORM_WINDOWS=1 -D_WIN32_WINNT=0x0600 $(CFLAGS)
 
 MANYWARNINGS = -Weverything -Wno-pointer-arith -Wno-unused-macros -Wno-shadow -Wno-cast-align -Wno-variadic-macros -Wno-missing-noreturn -Wno-missing-prototypes -Wno-unused-parameter -Wno-padded -Wno-missing-variable-declarations -Wno-unreachable-code-break -Wno-class-varargs -Wno-format-nonliteral -Wno-cast-qual -Wno-double-promotion -Wno-comma -Wno-strict-prototypes -Wno-extra-semi-stmt -Wno-used-but-marked-unused -Wno-unreachable-code-return -ferror-limit=1000