diff --git a/libs/port/compose.c b/libs/port/compose.c
index da49b448c72..8903d32634f 100644
--- a/libs/port/compose.c
+++ b/libs/port/compose.c
@@ -392,7 +392,7 @@ static inline int binary_search( WCHAR ch, int low, int high )
     return -1;
 }
 
-WCHAR wine_compose( const WCHAR *str )
+WCHAR DECLSPEC_HIDDEN wine_compose( const WCHAR *str )
 {
     int pos, idx = 1, start = 0, count = 70;
     for (;;)
diff --git a/libs/port/decompose.c b/libs/port/decompose.c
index 3e4a28b038a..34e83ec21e5 100644
--- a/libs/port/decompose.c
+++ b/libs/port/decompose.c
@@ -747,7 +747,7 @@ static const WCHAR table[4704] =
     0x05d1, 0x05bf, 0x05db, 0x05bf, 0x05e4, 0x05bf, 0x0000, 0x0000
 };
 
-unsigned int wine_decompose( WCHAR ch, WCHAR *dst, unsigned int dstlen )
+unsigned int DECLSPEC_HIDDEN wine_decompose( WCHAR ch, WCHAR *dst, unsigned int dstlen )
 {
     const WCHAR *ptr = table + table[table[ch >> 8] + ((ch >> 4) & 0x0f)] + 2 * (ch & 0xf);
     unsigned int res;
diff --git a/libs/port/digitmap.c b/libs/port/digitmap.c
index e6b398dbb7f..c2004977514 100644
--- a/libs/port/digitmap.c
+++ b/libs/port/digitmap.c
@@ -4,7 +4,7 @@
 
 #include "wine/unicode.h"
 
-const WCHAR wine_digitmap[5933] =
+const WCHAR DECLSPEC_HIDDEN wine_digitmap[5933] =
 {
     /* index */
     0x01d0, 0x0100, 0x0100, 0x0100, 0x0100, 0x0100, 0x028a, 0x0384,
@@ -786,7 +786,7 @@ const WCHAR wine_digitmap[5933] =
     0x0000, 0x0000
 };
 
-const WCHAR wine_compatmap[1497] =
+const WCHAR DECLSPEC_HIDDEN wine_compatmap[1497] =
 {
     /* index */
     0x0100, 0x0100, 0x0100, 0x0100, 0x0100, 0x0100, 0x0100, 0x0100,
diff --git a/libs/port/fold.c b/libs/port/fold.c
index 87a4a418faa..738469c8d77 100644
--- a/libs/port/fold.c
+++ b/libs/port/fold.c
@@ -22,13 +22,13 @@
 
 static inline WCHAR to_unicode_digit( WCHAR ch )
 {
-    extern const WCHAR wine_digitmap[];
+    extern const WCHAR wine_digitmap[] DECLSPEC_HIDDEN;
     return ch + wine_digitmap[wine_digitmap[ch >> 8] + (ch & 0xff)];
 }
 
 static inline WCHAR to_unicode_native( WCHAR ch )
 {
-    extern const WCHAR wine_compatmap[];
+    extern const WCHAR wine_compatmap[] DECLSPEC_HIDDEN;
     return ch + wine_compatmap[wine_compatmap[ch >> 8] + (ch & 0xff)];
 }
 
diff --git a/libs/port/mbtowc.c b/libs/port/mbtowc.c
index 9a4bc2381f1..fd7764eb9c7 100644
--- a/libs/port/mbtowc.c
+++ b/libs/port/mbtowc.c
@@ -22,7 +22,7 @@
 
 #include "wine/unicode.h"
 
-extern unsigned int wine_decompose( WCHAR ch, WCHAR *dst, unsigned int dstlen );
+extern unsigned int wine_decompose( WCHAR ch, WCHAR *dst, unsigned int dstlen ) DECLSPEC_HIDDEN;
 
 /* check the code whether it is in Unicode Private Use Area (PUA). */
 /* MB_ERR_INVALID_CHARS raises an error converting from 1-byte character to PUA. */
diff --git a/libs/port/utf8.c b/libs/port/utf8.c
index 5943ddadd72..f47561e4bff 100644
--- a/libs/port/utf8.c
+++ b/libs/port/utf8.c
@@ -22,7 +22,7 @@
 
 #include "wine/unicode.h"
 
-extern WCHAR wine_compose( const WCHAR *str );
+extern WCHAR wine_compose( const WCHAR *str ) DECLSPEC_HIDDEN;
 
 /* number of following bytes in sequence based on first byte value (for bytes above 0x7f) */
 static const char utf8_length[128] =
diff --git a/libs/port/wctomb.c b/libs/port/wctomb.c
index e7f35e5980e..65e4aa04f73 100644
--- a/libs/port/wctomb.c
+++ b/libs/port/wctomb.c
@@ -22,7 +22,7 @@
 
 #include "wine/unicode.h"
 
-extern WCHAR wine_compose( const WCHAR *str );
+extern WCHAR wine_compose( const WCHAR *str ) DECLSPEC_HIDDEN;
 
 /****************************************************************/
 /* sbcs support */
diff --git a/tools/make_unicode b/tools/make_unicode
index 19c6cb1196d..3a8d61081d8 100755
--- a/tools/make_unicode
+++ b/tools/make_unicode
@@ -1599,9 +1599,9 @@ sub dump_digit_folding($)
     print OUTPUT "/* DO NOT EDIT!! */\n\n";
     print OUTPUT "#include \"wine/unicode.h\"\n\n";
 
-    DUMP_CASE_TABLE( "wine_digitmap",  @digitmap_table );
+    DUMP_CASE_TABLE( "DECLSPEC_HIDDEN wine_digitmap",  @digitmap_table );
     print OUTPUT "\n";
-    DUMP_CASE_TABLE( "wine_compatmap", @compatmap_table );
+    DUMP_CASE_TABLE( "DECLSPEC_HIDDEN wine_compatmap", @compatmap_table );
     close OUTPUT;
     save_file($filename);
 }
@@ -2113,7 +2113,7 @@ static inline int binary_search( WCHAR ch, int low, int high )
     return -1;
 }
 
-WCHAR wine_compose( const WCHAR *str )
+WCHAR DECLSPEC_HIDDEN wine_compose( const WCHAR *str )
 {
     int pos, idx = 1, start = 0, count = $count;
     for (;;)
@@ -2218,7 +2218,7 @@ sub dump_decompose_table($)
 
     printf OUTPUT "\n};\n\n";
     print OUTPUT <<"EOF";
-unsigned int wine_decompose( WCHAR ch, WCHAR *dst, unsigned int dstlen )
+unsigned int DECLSPEC_HIDDEN wine_decompose( WCHAR ch, WCHAR *dst, unsigned int dstlen )
 {
     const WCHAR *ptr = table + table[table[ch >> 8] + ((ch >> 4) & 0x0f)] + 2 * (ch & 0xf);
     unsigned int res;