diff --git a/CHANGELOG b/CHANGELOG
index de407cf..852e813 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -125,3 +125,5 @@ WinDivert 1.4.1
     - Dual license WinDivert under LGPLv3 and GPLv2.
 WinDivert 1.4.2
     - Add workaround for pseudo checksum issue (see #134).
+WinDivert 1.4.3
+    - WinDivert.dll no longer depends on MSVCRT*.dll.
diff --git a/VERSION b/VERSION
index 9df886c..428b770 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.4.2
+1.4.3
diff --git a/dll/windivert.c b/dll/windivert.c
index cfcd346..3e773c7 100644
--- a/dll/windivert.c
+++ b/dll/windivert.c
@@ -39,7 +39,7 @@
 #include <winsock2.h>
 #include <windows.h>
 #include <winioctl.h>
-#include <ctype.h>
+
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -64,10 +64,15 @@
 #define ntohl(x)                        BYTESWAP32(x)
 #define htonl(x)                        BYTESWAP32(x)
 
+static BOOLEAN WinDivertIsXDigit(char c);
+static BOOLEAN WinDivertIsSpace(char c);
+static BOOLEAN WinDivertIsAlNum(char c);
+static char WinDivertToLower(char c);
 static BOOLEAN WinDivertStrLen(const wchar_t *s, size_t maxlen,
     size_t *lenptr);
 static BOOLEAN WinDivertStrCpy(wchar_t *dst, size_t dstlen,
     const wchar_t *src);
+static int WinDivertStrCmp(const char *s, const char *t);
 static BOOLEAN WinDivertAToI(const char *str, char **endptr, UINT32 *intptr);
 static BOOLEAN WinDivertAToX(const char *str, char **endptr, UINT32 *intptr);
 
@@ -694,6 +699,33 @@ extern BOOL WinDivertGetParam(HANDLE handle, WINDIVERT_PARAM param,
 /* REPLACEMENTS                                                              */
 /*****************************************************************************/
 
+static BOOLEAN WinDivertIsXDigit(char c)
+{
+    return (c >= '0' && c <= '9') ||
+           (c >= 'a' && c <= 'f') ||
+           (c >= 'A' && c <= 'F');
+}
+
+static BOOLEAN WinDivertIsSpace(char c)
+{
+    return (c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f' ||
+            c == '\v');
+}
+
+static BOOLEAN WinDivertIsAlNum(char c)
+{
+    return (c >= 'a' && c <= 'z') ||
+           (c >= 'A' && c <= 'Z') ||
+           (c >= '0' && c <= '9');
+}
+
+static char WinDivertToLower(char c)
+{
+    if (c >= 'A' && c <= 'Z')
+        return 'a' + (c - 'A');
+    return c;
+}
+
 static BOOLEAN WinDivertStrLen(const wchar_t *s, size_t maxlen,
     size_t *lenptr)
 {
@@ -728,6 +760,24 @@ static BOOLEAN WinDivertStrCpy(wchar_t *dst, size_t dstlen, const wchar_t *src)
     return TRUE;
 }
 
+static int WinDivertStrCmp(const char *s, const char *t)
+{
+    int cmp;
+    size_t i;
+    for (i = 0; ; i++)
+    {
+        cmp = s[i] - t[i];
+        if (cmp != 0)
+        {
+            return cmp;
+        }
+        if (s[i] == '\0')
+        {
+            return 0;
+        }
+    }
+}
+
 static BOOLEAN WinDivertAToI(const char *str, char **endptr, UINT32 *intptr)
 {
     size_t i = 0;
@@ -766,7 +816,7 @@ static BOOLEAN WinDivertAToX(const char *str, char **endptr, UINT32 *intptr)
     {
         i += 2;
     }
-    for (; str[i] && isxdigit(str[i]); i++)
+    for (; str[i] && WinDivertIsXDigit(str[i]); i++)
     {
         num0 = num;
         num *= 16;
@@ -776,7 +826,7 @@ static BOOLEAN WinDivertAToX(const char *str, char **endptr, UINT32 *intptr)
         }
         else
         {
-            num += (UINT32)(tolower(str[i]) - 'a') + 0x0A;
+            num += (UINT32)(WinDivertToLower(str[i]) - 'a') + 0x0A;
         }
         if (num0 > num)
         {
diff --git a/dll/windivert_helper.c b/dll/windivert_helper.c
index 2bd3325..f2ef991 100644
--- a/dll/windivert_helper.c
+++ b/dll/windivert_helper.c
@@ -709,7 +709,7 @@ extern BOOL WinDivertHelperParseIPv6Address(const char *str, UINT32 *addr_ptr)
             left = FALSE;
             str++;
         }
-        for (l = 0; l < 4 && isxdigit(*str); l++)
+        for (l = 0; l < 4 && WinDivertIsXDigit(*str); l++)
         {
             part_str[l] = *str;
             str++;
@@ -786,7 +786,7 @@ static PTOKEN_NAME WinDivertTokenLookup(PTOKEN_NAME token_names,
     while (hi >= lo)
     {
         mid = (lo + hi) / 2;
-        cmp = strcmp(token_names[mid].name, name);
+        cmp = WinDivertStrCmp(token_names[mid].name, name);
         if (cmp < 0)
         {
             lo = mid+1;
@@ -889,7 +889,7 @@ static ERROR WinDivertTokenizeFilter(const char *filter, WINDIVERT_LAYER layer,
             return MAKE_ERROR(WINDIVERT_ERROR_TOO_LONG, i);
         }
         memset(tokens[tp].val, 0, sizeof(tokens[tp].val));
-        while (isspace(filter[i]))
+        while (WinDivertIsSpace(filter[i]))
         {
             i++;
         }
@@ -974,11 +974,11 @@ static ERROR WinDivertTokenizeFilter(const char *filter, WINDIVERT_LAYER layer,
                 break;
         }
         token[0] = c;
-        if (isalnum(c) || c == '.' || c == ':')
+        if (WinDivertIsAlNum(c) || c == '.' || c == ':')
         {
             UINT32 num;
             char *end;
-            for (j = 1; j < TOKEN_MAXLEN && (isalnum(filter[i]) ||
+            for (j = 1; j < TOKEN_MAXLEN && (WinDivertIsAlNum(filter[i]) ||
                     filter[i] == '.' || filter[i] == ':'); j++, i++)
             {
                 token[j] = filter[i];
@@ -1995,7 +1995,7 @@ static ERROR WinDivertCompileFilter(const char *filter,
     }
 
     // Allocate memory pool for the compiler:
-    pool = (PPOOL)malloc(sizeof(POOL));
+    pool = (PPOOL)HeapAlloc(GetProcessHeap(), 0, sizeof(POOL));
     if (pool == NULL)
     {
         return MAKE_ERROR(WINDIVERT_ERROR_NO_MEMORY, 0);
@@ -2010,12 +2010,12 @@ static ERROR WinDivertCompileFilter(const char *filter,
     if (expr == NULL)
     {
         error = pool->error;
-        free(pool);
+        HeapFree(GetProcessHeap(), 0, pool);
         return error;
     }
     if (tokens[i].kind != TOKEN_END)
     {
-        free(pool);
+        HeapFree(GetProcessHeap(), 0, pool);
         return MAKE_ERROR(WINDIVERT_ERROR_UNEXPECTED_TOKEN, tokens[i].pos);
     }
 
@@ -2025,7 +2025,7 @@ static ERROR WinDivertCompileFilter(const char *filter,
         WINDIVERT_FILTER_RESULT_REJECT, stack);
     if (label < 0)
     {
-        free(pool);
+        HeapFree(GetProcessHeap(), 0, pool);
         return MAKE_ERROR(WINDIVERT_ERROR_TOO_LONG, 0);
     }
 
@@ -2034,7 +2034,7 @@ static ERROR WinDivertCompileFilter(const char *filter,
     {
         WinDivertEmitFilter(stack, label, label, object, obj_len);
     }
-    free(pool);
+    HeapFree(GetProcessHeap(), 0, pool);
 
     return MAKE_ERROR(WINDIVERT_ERROR_NONE, 0);
 }
diff --git a/mingw-build.sh b/mingw-build.sh
index 4125bea..1fcbee4 100644
--- a/mingw-build.sh
+++ b/mingw-build.sh
@@ -54,15 +54,16 @@ do
     if [ ! -d install/WDDK/$CPU ]
     then
         echo "WARNING: missing WDDK build; run wddk-build.bat first"
-        echo "SKIP WDDK-$CPU"
+        echo "SKIP MINGW-$CPU"
         continue
     fi
-    echo "BUILD WDDK-$CPU"
+    echo "BUILD MINGW-$CPU"
     CC="$ENV-gcc"
     COPTS="-shared -Wall -Wno-pointer-to-int-cast -O2 -Iinclude/ 
         -Wl,--enable-stdcall-fixup -Wl,--entry=${MANGLE}WinDivertDllEntry"
-    CLIBS="-lgcc -lmsvcrt -lkernel32 -ladvapi32"
+    CLIBS="-lgcc -lkernel32 -ladvapi32"
     STRIP="$ENV-strip"
+    DLLTOOL="$ENV-dlltool"
     if [ -x "`which $CC`" ]
     then
         echo "\tmake install/MINGW/$CPU..."
@@ -72,6 +73,10 @@ do
         $CC $COPTS -o "install/MINGW/$CPU/WinDivert.dll" \
             dll/windivert.o dll/windivert.def -nostdlib $CLIBS
         $STRIP "install/MINGW/$CPU/WinDivert.dll"
+        echo "\tbuild install/MINGW/$CPU/WinDivert.lib..."
+        $DLLTOOL --dllname install/MINGW/$CPU/WinDivert.dll \
+            --def dll/windivert.def \
+            --output-lib install/MINGW/$CPU/WinDivert.lib 2>/dev/null
         echo "\tbuild install/MINGW/$CPU/netdump.exe..."
         $CC -s -O2 -Iinclude/ examples/netdump/netdump.c \
             -o "install/MINGW/$CPU/netdump.exe" -lWinDivert -lws2_32 \
diff --git a/release-build.sh b/release-build.sh
index da36511..5204bb7 100644
--- a/release-build.sh
+++ b/release-build.sh
@@ -76,11 +76,8 @@ do
     then
         echo "\t\033[33mWARNING\033[0m: unsigned WinDivert32.sys..."
     fi
-    if [ $TARGET != MINGW ]
-    then
-        echo "\tcopy $INSTALL/x86/WinDivert.lib..."
-        cp install/$TARGET/i386/WinDivert.lib $INSTALL/x86
-    fi
+    echo "\tcopy $INSTALL/x86/WinDivert.lib..."
+    cp install/$TARGET/i386/WinDivert.lib $INSTALL/x86
     echo "\tcopy $INSTALL/x86/WinDivert.dll..."
     cp install/$TARGET/i386/WinDivert.dll $INSTALL/x86
     echo "\tcopy $INSTALL/x86/netdump.exe..."
@@ -104,11 +101,8 @@ do
         then
             echo -e "\t\033[33mWARNING\033[0m: unsigned WinDivert64.sys..."
         fi
-        if [ $TARGET != MINGW ]
-        then
-            echo "\tcopy $INSTALL/amd64/WinDivert.lib..."
-            cp install/$TARGET/amd64/WinDivert.lib $INSTALL/amd64
-        fi
+        echo "\tcopy $INSTALL/amd64/WinDivert.lib..."
+        cp install/$TARGET/amd64/WinDivert.lib $INSTALL/amd64
         echo "\tcopy $INSTALL/amd64/WinDivert.dll..."
         cp install/$TARGET/amd64/WinDivert.dll $INSTALL/amd64
         echo "\tcopy $INSTALL/amd64/netdump.exe..."