diff --git a/libics_binary.c b/libics_binary.c
index 7f43d29..3bde35b 100644
--- a/libics_binary.c
+++ b/libics_binary.c
@@ -69,6 +69,7 @@ Ics_Error IcsWritePlainWithStrides (void const* src, size_t const* dim,
    size_t curpos[ICS_MAXDIM];
    char const* data;
    int ii;
+   size_t jj;
 
    for (ii = 0; ii < ndims; ii++) {
       curpos[ii] = 0;
@@ -84,7 +85,7 @@ Ics_Error IcsWritePlainWithStrides (void const* src, size_t const* dim,
          }
       }
       else {
-         for (ii = 0; ii < dim[0]; ii++) {
+         for (jj = 0; jj < dim[0]; jj++) {
             if (fwrite (data, nbytes, 1, file) != 1) {
                return IcsErr_FWriteIds;
             }
@@ -195,7 +196,8 @@ Ics_Error IcsCopyIds (char const* infilename, size_t inoffset, char const* outfi
    FILE* in = 0;
    FILE* out = 0;
    char* buffer = 0;
-   int done = 0, n;
+   int done = 0;
+   size_t n;
 
    /* Open files */
    in = IcsFOpen (infilename, "rb");
diff --git a/libics_compress.c b/libics_compress.c
index d16ba4c..9e184ee 100644
--- a/libics_compress.c
+++ b/libics_compress.c
@@ -107,8 +107,8 @@ Ics_Error IcsReadCompress (Ics_Header* IcsStruct, void* outbuf, size_t len)
    size_t rsize;
    int block_mode;
    int maxbits;
-   int ii;
-   int offset;
+   size_t ii;
+   size_t offset;
    unsigned char *inbuf = NULL;
    unsigned char *htab = NULL;
    unsigned short *codetab = NULL;
diff --git a/libics_gzip.c b/libics_gzip.c
index 79d218f..3590935 100644
--- a/libics_gzip.c
+++ b/libics_gzip.c
@@ -118,7 +118,7 @@ Ics_Error IcsWriteZip (void const* inbuf, size_t len, FILE* file, int level)
 {
 #ifdef ICS_ZLIB
    z_stream stream;
-   Byte* outbuf;    /* output buffer */ int err, done, flush;
+   Byte* outbuf;    /* output buffer */ int err, flush;
    size_t total_count;
    unsigned int have;
    uLong crc;
@@ -208,6 +208,7 @@ Ics_Error IcsWriteZipWithStrides (void const* src,  size_t const* dim,
    size_t curpos[ICS_MAXDIM];
    char const* data;
    int ii, err, done;
+   size_t jj;
    size_t count, total_count = 0;
    uLong crc;
    int const contiguous_line = stride[0]==1;
@@ -262,7 +263,7 @@ Ics_Error IcsWriteZipWithStrides (void const* src,  size_t const* dim,
       }
       else {
          inbuf_ptr = inbuf;
-         for (ii = 0; ii < dim[0]; ii++) {
+         for (jj = 0; jj < dim[0]; jj++) {
             memcpy (inbuf_ptr, data, nbytes);
             data += stride[0]*nbytes;
             inbuf_ptr += nbytes;
diff --git a/libics_history.c b/libics_history.c
index 3173e06..c59d87c 100644
--- a/libics_history.c
+++ b/libics_history.c
@@ -135,7 +135,7 @@ Ics_Error IcsInternAddHistory (Ics_Header* ics, char const* key, char const* val
       hist = (Ics_History*)ics->History;
    }
    /* Reallocate if array is not large enough */
-   if (hist->NStr >= hist->Length) {
+   if ((size_t)hist->NStr >= hist->Length) {
       char** tmp = (char**)realloc (hist->Strings, (hist->Length+ICS_HISTARRAY_INCREMENT)*sizeof (char*));
       ICSTR( tmp == NULL, IcsErr_Alloc );
       hist->Strings = tmp;
diff --git a/libics_top.c b/libics_top.c
index 1c5f34b..14557ec 100644
--- a/libics_top.c
+++ b/libics_top.c
@@ -82,7 +82,8 @@ char const* ICSKEY_LABEL[] = {"x-position", "y-position", "z-position",
 Ics_Error IcsOpen (ICS* *ics, char const* filename, char const* mode)
 {
    ICSINIT;
-   int ii, version = 0, forcename = 0, forcelocale = 1, reading = 0, writing = 0;
+   int version = 0, forcename = 0, forcelocale = 1, reading = 0, writing = 0;
+   size_t ii;
 
    /* the mode string is one of: "r", "w", "rw", with "f" and/or "l" appended for
       reading and "1" or "2" appended for writing */
@@ -359,6 +360,7 @@ Ics_Error IcsGetROIData (ICS* ics, size_t const* p_offset, size_t const* p_size,
 {
    ICSDECL;
    int ii, sizeconflict = 0, p;
+   size_t jj;
    size_t imelsize, roisize, cur_loc, new_loc, bufsize;
    size_t curpos[ICS_MAXDIM];
    size_t stride[ICS_MAXDIM];
@@ -443,7 +445,7 @@ Ics_Error IcsGetROIData (ICS* ics, size_t const* p_offset, size_t const* p_size,
             break; /* stop reading on error */
          }
          cur_loc += bufsize;
-         for (ii=0; ii<size[0]; ii+=sampling[0]) {
+         for (jj=0; jj<size[0]; jj+=sampling[0]) {
             memcpy (dest, buf+ii*imelsize, imelsize);
             dest += imelsize;
          }
@@ -509,6 +511,7 @@ Ics_Error IcsGetDataWithStrides (ICS* ics, void* p_dest, size_t n, size_t const*
 {
    ICSDECL;
    int ii, p;
+   size_t jj;
    size_t imelsize, lastpixel, bufsize;
    size_t curpos[ICS_MAXDIM];
    size_t b_stride[ICS_MAXDIM];
@@ -556,8 +559,8 @@ Ics_Error IcsGetDataWithStrides (ICS* ics, void* p_dest, size_t n, size_t const*
          if (error != IcsErr_Ok) {
             break; /* stop reading on error */
          }
-         for (ii = 0; ii < ics->Dim[0].Size; ii++) {
-            memcpy (out, buf+ii*imelsize, imelsize);
+         for (jj = 0; jj < ics->Dim[0].Size; jj++) {
+            memcpy (out, buf+jj*imelsize, imelsize);
             out += stride[0]*imelsize;
          }
          for (ii = 1; ii < p; ii++) {