diff --git a/lib/xlsxio_read.c b/lib/xlsxio_read.c
index 42a9830..e02de1c 100644
--- a/lib/xlsxio_read.c
+++ b/lib/xlsxio_read.c
@@ -704,7 +704,10 @@ unzGetGlobalInfo(data->zip, &zipglobalinfo);
           buf[buflen - 1] = 0;
           while ((status = unzGetCurrentFileInfo(data->zip, NULL, buf, buflen, NULL, 0, NULL, 0)) == UNZ_OK && buf[buflen - 1] != 0) {
             buflen += UNZIP_FILENAME_BUFFER_STEP;
-            buf = (char*)realloc(buf, buflen);
+            if ((buf = (char*)realloc(buf, buflen)) == NULL) {
+              //memory allocation error
+              return;
+            }
             buf[buflen - 1] = 0;
           }
           if (status != UNZ_OK)
@@ -1264,12 +1267,10 @@ void data_sheet_expat_callback_value_data (void* callbackdata, const XML_Char* b
 {
   struct data_sheet_callback_data* data = (struct data_sheet_callback_data*)callbackdata;
   if (data->cell_string_type != none) {
-    XML_Char *temp = XML_Char_realloc(data->celldata, data->celldatalen + buflen + 1);
-    if (temp == NULL) {
+    if ((data->celldata = XML_Char_realloc(data->celldata, data->celldatalen + buflen + 1)) == NULL) {
       //memory allocation error
       data->celldatalen = 0;
     } else {
-      data->celldata = temp;
       //add new data to value buffer
       XML_Char_poscpy(data->celldata, data->celldatalen, buf, buflen);
       data->celldatalen += buflen;
diff --git a/lib/xlsxio_read_sharedstrings.c b/lib/xlsxio_read_sharedstrings.c
index e59598f..b83de84 100644
--- a/lib/xlsxio_read_sharedstrings.c
+++ b/lib/xlsxio_read_sharedstrings.c
@@ -195,12 +195,10 @@ void shared_strings_callback_find_shared_string_end (void* callbackdata, const X
 void shared_strings_callback_string_data (void* callbackdata, const XML_Char* buf, int buflen)
 {
   struct shared_strings_callback_data* data = (struct shared_strings_callback_data*)callbackdata;
-  XML_Char *temp = XML_Char_realloc(data->text, data->textlen + buflen);
-  if (temp == NULL) {
+  if ((data->text = XML_Char_realloc(data->text, data->textlen + buflen)) == NULL) {
     //memory allocation error
     data->textlen = 0;
   } else {
-    data->text = temp;
     XML_Char_poscpy(data->text, data->textlen, buf, buflen);
     data->textlen += buflen;
   }
diff --git a/lib/xlsxio_write.c b/lib/xlsxio_write.c
index 7175aa3..f065855 100644
--- a/lib/xlsxio_write.c
+++ b/lib/xlsxio_write.c
@@ -158,7 +158,7 @@ const char* docprops_core_xml =
 const char* docprops_app_xml =
   XML_HEADER
   "<Properties xmlns=\"http://schemas.openxmlformats.org/officeDocument/2006/extended-properties\" xmlns:vt=\"http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes\">" OPTIONAL_LINE_BREAK
-  "<Application>" XLSXIOWRITE_NAME " " XLSXIO_VERSION_STRING "</Application>" OPTIONAL_LINE_BREAK 
+  "<Application>" XLSXIOWRITE_NAME " " XLSXIO_VERSION_STRING "</Application>" OPTIONAL_LINE_BREAK
   "</Properties>" OPTIONAL_LINE_BREAK;
 
 const char* rels_xml =
@@ -399,10 +399,10 @@ char* str_replace (char** s, size_t pos, size_t len, char* replacement)
   if (pos + len > totallen)
     len = totallen - pos;
   if (replacementlen > len) {
-    char *temp = (char*)realloc(*s, totallen - len + replacementlen + 1);
-    if (temp == NULL)
+    if ((*s = (char*)realloc(*s, totallen - len + replacementlen + 1)) == NULL) {
+      //memory allocation error
       return NULL;
-    *s = temp;
+    }
   }
   memmove(*s + pos + replacementlen, *s + pos + len, totallen - pos - len + 1);
   memcpy(*s + pos, replacement, replacementlen);
@@ -457,8 +457,10 @@ int vappend_data (char** pdata, size_t* pdatalen, const char* format, va_list ar
   if ((len = vsnprintf(NULL, 0, format, args)) < 0)
     return -1;
   va_end(args);
-  if ((*pdata = (char*)realloc(*pdata, *pdatalen + len + 1)) == NULL)
+  if ((*pdata = (char*)realloc(*pdata, *pdatalen + len + 1)) == NULL) {
+    //memory allocation error
     return -1;
+  }
   vsnprintf(*pdata + *pdatalen, len + 1, format, args2);
   va_end(args2);
   *pdatalen += len;
@@ -487,10 +489,10 @@ int append_data (char** pdata, size_t* pdatalen, const char* format, ...)
   va_end(args);
   if (len < 0)
     return -1;
-  char *temp = (char*)realloc(*pdata, *pdatalen + len + 1);
-  if (temp == NULL)
+  if ((*pdata = (char*)realloc(*pdata, *pdatalen + len + 1)) == NULL) {
+    //memory allocation error
     return -1;
-  *pdata = temp;
+  }
   va_start(args, format);
   vsnprintf(*pdata + *pdatalen, len + 1, format, args);
   va_end(args);
@@ -510,8 +512,10 @@ int insert_data (char** pdata, size_t* pdatalen, size_t pos, const char* format,
   va_end(args);
   if (len < 0)
     return -1;
-  if ((*pdata = (char*)realloc(*pdata, *pdatalen + len + 1)) == NULL)
+  if ((*pdata = (char*)realloc(*pdata, *pdatalen + len + 1)) == NULL) {
+    //memory allocation error
     return -1;
+  }
   if (pos > *pdatalen)
     pos = *pdatalen;
   if (pos < *pdatalen)
diff --git a/src/xlsxio_csv2xlsx.c b/src/xlsxio_csv2xlsx.c
index 8d05028..82639cd 100644
--- a/src/xlsxio_csv2xlsx.c
+++ b/src/xlsxio_csv2xlsx.c
@@ -36,10 +36,11 @@ THE SOFTWARE.
 int append_buffer_data (char** pdata, size_t* pdatalen, const char* bufferdata, size_t bufferdatalen)
 {
   //allocate larger data buffer, abort in case of memory allocation error
-  char *temp = (char*)realloc(*pdata, *pdatalen + bufferdatalen + 1);
-  if (temp == NULL)
+  if ((*pdata = (char*)realloc(*pdata, *pdatalen + bufferdatalen + 1)) == NULL) {
+    //memory allocation error
+    *pdatalen = 0;
     return 1;
-  *pdata = temp;
+  }
   //append new data and adjust length
   memcpy(*pdata + *pdatalen, bufferdata, bufferdatalen);
   *pdatalen += bufferdatalen;