diff --git a/src/hb-icu-le/FontTableCache.h b/src/hb-icu-le/FontTableCache.h
index d41d7c7268407db4a1bb2862c175c682ff5ec0ad..f956f885c1b6e9530961c97e20505ee5cf14ca56 100644
--- a/src/hb-icu-le/FontTableCache.h
+++ b/src/hb-icu-le/FontTableCache.h
@@ -13,6 +13,9 @@
 #include <hb-blob.h>
 
 #include "layout/LETypes.h"
+#include "letest.h"
+
+HB_BEGIN_VISIBILITY
 
 U_NAMESPACE_USE
 
@@ -40,5 +43,6 @@ private:
     le_int32 fTableCacheSize;
 };
 
-#endif
+HB_END_VISIBILITY
 
+#endif
diff --git a/src/hb-icu-le/PortableFontInstance.cpp b/src/hb-icu-le/PortableFontInstance.cpp
index f4eb17168a1c399c4ce8aa4417aacffbe4923e9e..c38e2b1143d24e263f5c9d19078ebf545e62bbd9 100644
--- a/src/hb-icu-le/PortableFontInstance.cpp
+++ b/src/hb-icu-le/PortableFontInstance.cpp
@@ -24,45 +24,6 @@
 
 #include <string.h>
 
-//
-// Finds the high bit by binary searching
-// through the bits in n.
-//
-le_int8 PortableFontInstance::highBit(le_int32 value)
-{
-    if (value <= 0) {
-        return -32;
-    }
-
-    le_uint8 bit = 0;
-
-    if (value >= 1 << 16) {
-        value >>= 16;
-        bit += 16;
-    }
-
-    if (value >= 1 << 8) {
-        value >>= 8;
-        bit += 8;
-    }
-
-    if (value >= 1 << 4) {
-        value >>= 4;
-        bit += 4;
-    }
-
-    if (value >= 1 << 2) {
-        value >>= 2;
-        bit += 2;
-    }
-
-    if (value >= 1 << 1) {
-        value >>= 1;
-        bit += 1;
-    }
-
-    return bit;
-}
 
 PortableFontInstance::PortableFontInstance(hb_face_t *face, float xScale, float yScale, LEErrorCode &status)
     : fFace(face), fXScale(xScale), fYScale(yScale), fUnitsPerEM(0), fAscent(0), fDescent(0), fLeading(0),
diff --git a/src/hb-icu-le/PortableFontInstance.h b/src/hb-icu-le/PortableFontInstance.h
index 4bfeb364ba8a8578dd37a9ff24ec308b0a770ed3..ff48311d58d70d3c09e80c5f0267b02647bf864a 100644
--- a/src/hb-icu-le/PortableFontInstance.h
+++ b/src/hb-icu-le/PortableFontInstance.h
@@ -21,11 +21,14 @@
 
 #include "layout/LETypes.h"
 #include "layout/LEFontInstance.h"
+#include "letest.h"
 
 #include "FontTableCache.h"
 
 #include "cmaps.h"
 
+HB_BEGIN_VISIBILITY
+
 class PortableFontInstance : public LEFontInstance, protected FontTableCache
 {
 private:
@@ -51,8 +54,6 @@ private:
     le_uint16 fNumGlyphs;
     le_uint16 fNumLongHorMetrics;
 
-    static le_int8 highBit(le_int32 value);
-
     void getMetrics();
 
     CMAPMapper *findUnicodeMapper();
@@ -109,4 +110,6 @@ public:
 
 };
 
+HB_END_VISIBILITY
+
 #endif
diff --git a/src/hb-icu-le/cmaps.cpp b/src/hb-icu-le/cmaps.cpp
index 87087aaa0d249a8ef41f3f5a88ea41164f920150..d03ee710f0fef3283465faa802f7794b8b67b032 100644
--- a/src/hb-icu-le/cmaps.cpp
+++ b/src/hb-icu-le/cmaps.cpp
@@ -18,7 +18,7 @@
 // Finds the high bit by binary searching
 // through the bits in value.
 //
-le_int8 highBit(le_uint32 value)
+static inline le_int8 highBit(le_uint32 value)
 {
     le_uint8 bit = 0;
 
diff --git a/src/hb-icu-le/cmaps.h b/src/hb-icu-le/cmaps.h
index fcad788bb281a804c2cc88e2442395bb2cfe099a..cf73f3a222c39dcab0e26a6ce413179019a19415 100644
--- a/src/hb-icu-le/cmaps.h
+++ b/src/hb-icu-le/cmaps.h
@@ -13,6 +13,8 @@
 #include "letest.h"
 #include "sfnt.h"
 
+HB_BEGIN_VISIBILITY
+
 class CMAPMapper
 {
 public:
@@ -80,5 +82,6 @@ inline CMAPMapper::~CMAPMapper()
 {
 }
 
-#endif
+HB_END_VISIBILITY
 
+#endif
diff --git a/src/hb-icu-le/letest.h b/src/hb-icu-le/letest.h
index f924ca862b4ab3d505e9f8edbd35dd703a52bd27..ff564ba6b5c00a8c9ddb3121a6cff2f4014bef76 100644
--- a/src/hb-icu-le/letest.h
+++ b/src/hb-icu-le/letest.h
@@ -14,12 +14,24 @@
 #ifndef __LETEST_H
 #define __LETEST_H
 
+
+#if defined(__GNUC__) && (__GNUC__ >= 4) && !defined(__MINGW32__)
+# define HB_BEGIN_VISIBILITY _Pragma ("GCC visibility push(hidden)")
+# define HB_END_VISIBILITY _Pragma ("GCC visibility pop")
+#else
+# define HB_BEGIN_VISIBILITY
+# define HB_END_VISIBILITY
+#endif
+
+
 #include "layout/LETypes.h"
 /*#include "unicode/ctest.h"*/
 
 #include <stdlib.h>
 #include <string.h>
 
+HB_BEGIN_VISIBILITY
+
 U_NAMESPACE_USE
 
 #define ARRAY_SIZE(array) (sizeof array / sizeof array[0])
@@ -46,4 +58,6 @@ typedef struct TestResult TestResult;
 
 //U_CFUNC void addCTests(TestNode **root);
 
+HB_END_VISIBILITY
+
 #endif
diff --git a/src/hb-icu-le/sfnt.h b/src/hb-icu-le/sfnt.h
index 4a8f2f39877937430082e789af1f1c93ca435e28..feec0ade3448dca54bf2d48fb941469e84ad8e0f 100644
--- a/src/hb-icu-le/sfnt.h
+++ b/src/hb-icu-le/sfnt.h
@@ -9,6 +9,9 @@
 #define __SFNT_H
 
 #include "layout/LETypes.h"
+#include "letest.h"
+
+HB_BEGIN_VISIBILITY
 
 U_NAMESPACE_USE
 
@@ -445,5 +448,6 @@ struct NAMETable
 typedef struct NAMETable NAMETable;
 #endif
 
-#endif
+HB_END_VISIBILITY
 
+#endif