diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 808418a6..a1162e3a 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -26,7 +26,7 @@
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
-#include "zstd_compress.h"
+#include "zstd_compress_internal.h"
 #include "zstd_fast.h"
 #include "zstd_double_fast.h"
 #include "zstd_lazy.h"
diff --git a/lib/compress/zstd_compress.h b/lib/compress/zstd_compress_internal.h
similarity index 99%
rename from lib/compress/zstd_compress.h
rename to lib/compress/zstd_compress_internal.h
index bb508795..e01d532c 100644
--- a/lib/compress/zstd_compress.h
+++ b/lib/compress/zstd_compress_internal.h
@@ -9,7 +9,7 @@
  */
 
 /* This header contains definitions
- * that shall only be used by modules from within lib/compress.
+ * that shall **only** be used by modules within lib/compress.
  */
 
 #ifndef ZSTD_COMPRESS_H
diff --git a/lib/compress/zstd_double_fast.c b/lib/compress/zstd_double_fast.c
index 876a3604..fee5127c 100644
--- a/lib/compress/zstd_double_fast.c
+++ b/lib/compress/zstd_double_fast.c
@@ -8,6 +8,7 @@
  * You may select, at your option, one of the above-listed licenses.
  */
 
+#include "zstd_compress_internal.h"
 #include "zstd_double_fast.h"
 
 
diff --git a/lib/compress/zstd_double_fast.h b/lib/compress/zstd_double_fast.h
index 3dba6c71..75e04158 100644
--- a/lib/compress/zstd_double_fast.h
+++ b/lib/compress/zstd_double_fast.h
@@ -11,12 +11,13 @@
 #ifndef ZSTD_DOUBLE_FAST_H
 #define ZSTD_DOUBLE_FAST_H
 
-#include "zstd_compress.h"
-
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
+#include "mem.h"      /* U32 */
+#include "zstd.h"     /* ZSTD_CCtx, size_t */
+
 void ZSTD_fillDoubleHashTable(ZSTD_CCtx* cctx, const void* end, const U32 mls);
 size_t ZSTD_compressBlock_doubleFast(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
 size_t ZSTD_compressBlock_doubleFast_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
diff --git a/lib/compress/zstd_fast.c b/lib/compress/zstd_fast.c
index 2e057017..7b56c3d6 100644
--- a/lib/compress/zstd_fast.c
+++ b/lib/compress/zstd_fast.c
@@ -8,6 +8,7 @@
  * You may select, at your option, one of the above-listed licenses.
  */
 
+#include "zstd_compress_internal.h"
 #include "zstd_fast.h"
 
 
diff --git a/lib/compress/zstd_fast.h b/lib/compress/zstd_fast.h
index 4205141a..d8b77719 100644
--- a/lib/compress/zstd_fast.h
+++ b/lib/compress/zstd_fast.h
@@ -11,12 +11,13 @@
 #ifndef ZSTD_FAST_H
 #define ZSTD_FAST_H
 
-#include "zstd_compress.h"
-
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
+#include "mem.h"      /* U32 */
+#include "zstd.h"     /* ZSTD_CCtx, size_t */
+
 void ZSTD_fillHashTable(ZSTD_CCtx* zc, const void* end, const U32 mls);
 size_t ZSTD_compressBlock_fast(ZSTD_CCtx* ctx,
                          const void* src, size_t srcSize);
diff --git a/lib/compress/zstd_lazy.c b/lib/compress/zstd_lazy.c
index 2a7f6a0f..d80e06f7 100644
--- a/lib/compress/zstd_lazy.c
+++ b/lib/compress/zstd_lazy.c
@@ -8,6 +8,7 @@
  * You may select, at your option, one of the above-listed licenses.
  */
 
+#include "zstd_compress_internal.h"
 #include "zstd_lazy.h"
 
 
diff --git a/lib/compress/zstd_lazy.h b/lib/compress/zstd_lazy.h
index a9c4daed..74e1fd69 100644
--- a/lib/compress/zstd_lazy.h
+++ b/lib/compress/zstd_lazy.h
@@ -11,12 +11,13 @@
 #ifndef ZSTD_LAZY_H
 #define ZSTD_LAZY_H
 
-#include "zstd_compress.h"
-
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
+#include "mem.h"    /* U32 */
+#include "zstd.h"   /* ZSTD_CCtx, size_t */
+
 U32 ZSTD_insertAndFindFirstIndex (ZSTD_CCtx* zc, const BYTE* ip, U32 mls);
 void ZSTD_updateTree(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls);
 void ZSTD_updateTree_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls);
diff --git a/lib/compress/zstd_ldm.h b/lib/compress/zstd_ldm.h
index d6d3d42c..8f12c677 100644
--- a/lib/compress/zstd_ldm.h
+++ b/lib/compress/zstd_ldm.h
@@ -10,12 +10,13 @@
 #ifndef ZSTD_LDM_H
 #define ZSTD_LDM_H
 
-#include "zstd_compress.h"
-
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
+#include "zstd_compress_internal.h"   /* ldmParams_t, U32 */
+#include "zstd.h"   /* ZSTD_CCtx, size_t */
+
 /*-*************************************
 *  Long distance matching
 ***************************************/
diff --git a/lib/compress/zstd_opt.c b/lib/compress/zstd_opt.c
index e349bb99..f416c15f 100644
--- a/lib/compress/zstd_opt.c
+++ b/lib/compress/zstd_opt.c
@@ -8,8 +8,9 @@
  * You may select, at your option, one of the above-listed licenses.
  */
 
+#include "zstd_compress_internal.h"
 #include "zstd_opt.h"
-#include "zstd_lazy.h"
+#include "zstd_lazy.h"   /* ZSTD_updateTree, ZSTD_updateTree_extDict */
 
 
 #define ZSTD_LITFREQ_ADD    2
diff --git a/lib/compress/zstd_opt.h b/lib/compress/zstd_opt.h
index 816a1fab..82e810c2 100644
--- a/lib/compress/zstd_opt.h
+++ b/lib/compress/zstd_opt.h
@@ -11,12 +11,12 @@
 #ifndef ZSTD_OPT_H
 #define ZSTD_OPT_H
 
-#include "zstd_compress.h"
-
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
+#include "zstd.h"   /* ZSTD_CCtx, size_t */
+
 size_t ZSTD_compressBlock_btopt(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
 size_t ZSTD_compressBlock_btultra(ZSTD_CCtx* ctx, const void* src, size_t srcSize);
 
diff --git a/lib/compress/zstdmt_compress.c b/lib/compress/zstdmt_compress.c
index eb17f970..0b9173f3 100644
--- a/lib/compress/zstdmt_compress.c
+++ b/lib/compress/zstdmt_compress.c
@@ -24,7 +24,7 @@
 #include <string.h>      /* memcpy, memset */
 #include "pool.h"        /* threadpool */
 #include "threading.h"   /* mutex */
-#include "zstd_compress.h"  /* MIN, ERROR, ZSTD_*, ZSTD_highbit32 */
+#include "zstd_compress_internal.h"  /* MIN, ERROR, ZSTD_*, ZSTD_highbit32 */
 #include "zstdmt_compress.h"