diff --git a/src/node_internals.h b/src/node_internals.h
index 31076551e70c46..8f7929994f3243 100644
--- a/src/node_internals.h
+++ b/src/node_internals.h
@@ -39,11 +39,6 @@
 #include <string>
 #include <vector>
 
-// Custom constants used by both node_constants.cc and node_zlib.cc
-#define Z_MIN_WINDOWBITS 8
-#define Z_MAX_WINDOWBITS 15
-#define Z_DEFAULT_WINDOWBITS 15
-
 struct sockaddr;
 
 namespace node {
diff --git a/src/node_zlib.cc b/src/node_zlib.cc
index 2a2466052c92a5..b8733229b0b06b 100644
--- a/src/node_zlib.cc
+++ b/src/node_zlib.cc
@@ -71,6 +71,9 @@ namespace {
 #define Z_MIN_LEVEL -1
 #define Z_MAX_LEVEL 9
 #define Z_DEFAULT_LEVEL Z_DEFAULT_COMPRESSION
+#define Z_MIN_WINDOWBITS 8
+#define Z_MAX_WINDOWBITS 15
+#define Z_DEFAULT_WINDOWBITS 15
 
 #define ZLIB_ERROR_CODES(V)      \
   V(Z_OK)                        \