diff --git a/CMakeLists.txt b/CMakeLists.txt
index e72278fc..6604b20d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -41,7 +41,7 @@ set(FLEECE_BASE_SRC Fleece/Support/Backtrace.cc
                     Fleece/Support/RefCounted.cc
                     Fleece/Support/Writer.cc
                     Fleece/Support/betterassert.cc
-                    Fleece/Support/FLSlice.cc
+                    Fleece/API_Impl/FLSlice.cc
                     Fleece/Support/slice.cc
                     Fleece/Support/varint.cc
                     vendor/libb64/cdecode.c
diff --git a/Fleece/API_Impl/FLSlice.cc b/Fleece/API_Impl/FLSlice.cc
index 7a0efe68..35a94ec2 100644
--- a/Fleece/API_Impl/FLSlice.cc
+++ b/Fleece/API_Impl/FLSlice.cc
@@ -16,7 +16,10 @@
 // limitations under the License.
 //
 
-#include "FLSlice.h"
+#include "fleece/FLSlice.h"
+#include <atomic>
+#include <cstddef>
+#include "betterassert.hh"
 
 
 bool FLSlice_Equal(FLSlice a, FLSlice b) {
@@ -83,10 +86,6 @@ namespace fleece {
             free(self);
         }
 
-        static sharedBuffer* fromBuf(const void *buf) {
-            return offsetby((sharedBuffer*)buf, -((long long)offsetof(sharedBuffer, _buf)));
-        }
-
         inline void retain() noexcept {
             assert(isHeapAligned(this));
             ++_refCount;
@@ -99,6 +98,10 @@ namespace fleece {
         }
     };
 
+    static sharedBuffer* bufferFromBuf(const void *buf) {
+        return (sharedBuffer*)((uint8_t*)buf  - offsetof(sharedBuffer, _buf));
+    }
+
 }
 
 using namespace fleece;
@@ -137,13 +140,13 @@ void _FLBuf_Release(const void*);
 
 void _FLBuf_Retain(const void *buf) {
     if (buf)
-        sharedBuffer::fromBuf(buf)->retain();
+        bufferFromBuf(buf)->retain();
 }
 
 
 void _FLBuf_Release(const void *buf) {
     if (buf)
-        sharedBuffer::fromBuf(buf)->release();
+        bufferFromBuf(buf)->release();
 }
 
 
diff --git a/Fleece/Support/Fleece.exp b/Fleece/Support/Fleece.exp
index fb995a94..ee9cba74 100644
--- a/Fleece/Support/Fleece.exp
+++ b/Fleece/Support/Fleece.exp
@@ -8,8 +8,8 @@ _kFLEmptyDict
 
 _FLSlice_Equal
 _FLSlice_Compare
-_FLSliceResult_Retain
-_FLSliceResult_Release
+__FLBuf_Retain
+__FLBuf_Release
 
 _FLDoc_FromResultData
 _FLDoc_FromJSON
diff --git a/Fleece/Support/betterassert.hh b/Fleece/Support/betterassert.hh
index bb2d714b..90044df8 100644
--- a/Fleece/Support/betterassert.hh
+++ b/Fleece/Support/betterassert.hh
@@ -30,9 +30,9 @@
 #endif // assert_always
 
 
-#ifndef NDEBUG
-
-    #undef assert
+#undef assert
+#ifdef NDEBUG
+    #define assert(e) ((void)0)
+#else
     #define assert(e) assert_always(e)
-
 #endif //NDEBUG
diff --git a/cmake/platform_base.cmake b/cmake/platform_base.cmake
index 847e68b8..68f1a550 100644
--- a/cmake/platform_base.cmake
+++ b/cmake/platform_base.cmake
@@ -8,6 +8,7 @@ function(set_source_files_base)
     set(
         ${BASE_SSS_RESULT}
         Fleece/API_Impl/Fleece.cc
+        Fleece/API_Impl/FLSlice.cc
         Fleece/Core/Array.cc
         Fleece/Core/DeepIterator.cc
         Fleece/Core/Dict.cc
@@ -77,4 +78,4 @@ function(set_test_source_files_base)
         Experimental/KeyTree.cc
         PARENT_SCOPE
     )
-endfunction()
\ No newline at end of file
+endfunction()